Exporting on the same sequence settings as the clip doubles the size of the output file
Ok there's a few different aspects to this, so here goes. 


  I am trying to create an edit/archive render of my videos captured from Sony A6000. The recording format is: 1080p 50FPS H.264 Codec.


Not sure what you mean here, but I assume you want to prepare your footage for archiving purposes? The best way to archive your footage is to leave it as it is. I can't stress this enough. Compressing your footage to save a few gigabytes is a very bad idea. Storage is cheap, you can get an external HDD with 2~3 TB for less than a hundred bucks. Or unlimited cloud storage on Amazon for 70 bucks a year. There's really no reason to compress your original footage, but there are many downsides. If you want to save space at all, you will need to use a lossy codec with a lower bitrate than the original. That means you get artifacts in your video, temporal interpolation (meaning not every frame in your video is saved as a whole, which is quite bad if you want to edit the footage later on and overall reduced quality. You also get chroma subsampling which reduces the available color information, which is bad if you want to color grade your footage later on. So in general, if you want to archive your footage, always archive the original files. 

On the other hand, if you have no use for your video files because they are kind of bad and you want to keep them 'just in case', throw them out. You won't look at them again and they are just wasting space. 

Anyway, rant over. In case I misunderstood your intentions or you still want to proceed, here's the actual answer. 


  I basically want an uncompressed edit or archive render to save the video without any compression or downscaling or without reducing the FPS as well.


If you actually use a lossless or visually lossless codec, you will only increase your filesize massively. H.264 (the format of your original footage) is a lossy codec meaning it's heavily compressed. The thing is, while exporting to an uncompressed format will increase your filesize, it won't actually increase the video quality, as the information already lost in the compressed H.264 files can't be magically recovered. So there's really no reason to export to an uncompressed format except for editing purposes (formats with temporal interpolation can be laggy during editing, because only I-frames are saved in full, B-frames are stored as the difference to the last I-frame or preceding frame). 

So there's really no reason to convert your footage to either an uncompressed or a heavily compressed version. Anyway …


  Basically, to replicate the issue you just have to create a sequence from clip and export to the sequence settings and the exported file size is double the original size.


Your final video output is dependent on your sequence settings and your export settings. If you created the sequence directly from a footage clip, they will match the clip parameters, so you're good here. 

Regarding the export settings, the output file size is mainly dependent on the bitrate (which is literally the amount of information, i.e. bits per second of your video). To change the output size, you will need to change your Target Bitrate (the setting may have a slightly different name if you use formats other than H.264). Depending on your version of Premiere Pro, the steps to change the bitrate while using the Match Sequence Settings option differ. For completion's sake, I will include instructions for both CC and older versions. 

Premiere Pro CC

The Match Sequence Option can be toggled on and off for every parameter individually. So you simply need to uncheck the option for the Target and Maximum Bitrate setting, then you can change the bitrate to whatever you want.

Premiere Pro CS6 and older

Unfortunately, with older versions you only get the Match Sequence Settings options in the form of a checkbox at the top that looks most export settings when checked. I'm actually not sure if that includes the bitrate (it's been a while since I had to use non-CC versions of Premiere). I would have said it does not (as claimed by stib in the comments), but since you said that option is locked, try unchecking Match Sequence Settings and see if the bitrate options become available. Unfortunately this will also reset the rest of your settings to your selected Preset, which might not be what you want. So you have to adjust the Export Settings. You will want to match most of those to your original footage parameters, I wouldn't change to much unless you know what you are doing. To find out all technical parameters of your footage, download something like MediaInfo and inspect one of your video files in it. For example, the video you linked was shot at a 1920x1080 resolution, 50 fps, progressive (not interlaced) and with an audio bitrate of 256kbps. Change the export settings accordingly, and then change the bitrate setting to your liking. 



You will notice that the estimated filesize correlates directly to the chosen bitrate. Your original footage was shot with a variable bitrate, at 26Mbps average. If you want to compress your footage down, use a lower bitrate. If you want to preserve as much quality as possible, use a bitrate at least as high as the original bitrate. But again, I can't recommend either of those things, just keep your footage as it is.

If you export for viewing purposes, experiment with different bitrates to find the lowest one that still yields a quality that is acceptable to you for your specific purpose. Here's some math that will help you understand the relation between bitrate and resulting filesize. 



Update in response to your comments


  I don't want to store the actual recording because it's not consumable without editing. I want to do my editing save it as one big file and archive it, later I can use this edited ready to go archive file and can export or reencode it to medium


The problem is that those are two very different purposes and it's not really practical to do both with only one file.

For your edited output video that you want to show to the world, you'll want to trade off some amount of quality in return for a reduced filesize. Whatever you intend to do with this video, having huge files (like, gigabits of data per minute) is pretty detrimental. You can't send them to people with slow internet connections, you can't transport them on small USB sticks ... and people with slower computers might actually have trouble viewing your video at all, because their hardware can't keep up. So you want to find the lowest possible bitrate that still yields acceptable quality. On a related note:


  If you pause frames of original footage and rendered footage, the original one looks sharper. 


Yeah, but who is gonna do that? You are probably paying closer attention to your video than anyone in your audience will. Of course, you also gotta take into consideration the purpose, target audience and medium in which your video will be displayed (I can only make assumptions here), but for general prosumer-ish/home productions, my point above stands.


  later I can use this edited ready to go archive file and can export or reencode it to medium I want or even do further editing If need be


That's a very bad idea. The thing is, you're exporting from a compressed format to a compressed format. If you use the exported file to export to another format, your final video will have gone through three export cycles already. It's just gotta hurt your overall video quality. Just keep your original files, your Premiere Pro project file, and everything else that is part of your project in one folder and back it up somewhere safe. If you in 20 years from now decide you need your video in H.269 for some reason, open up the original project and export from that (assuming Adobe's SaaS model hasn't crashed by then, just saying). Of course you can also export a version of your video with a visually uncompressed codec, or as an image sequence or something like that (in fact, depending on your production workflow this might be an intermediate step, but not as the final version). However, that file will be huge, so you won't have really achieved anything in terms of filesize. 


  It produces as acceptable file size but the quality is definitely not the same.


If you used a bitrate that is close to the bitrate of your original files (~26 Mbit/s) and 2-Pass encoding, I find that hard to believe. I usually use like 6~8 Mbit/s for my exports, and I rarely spot any artifacts in the output at all. I think it's much more likely that you messed up some other setting in your Sequence or Export Settings, and that is what's causing the problems with your output quality. Feel free to open a new topic regarding this problem, this thread is really getting out of hand …