Clearing out blocked weeping tile
My suggestion is to dig it up from outside and work through the pipe from there over under the basement floor. If it is a simple blockage you should be able to get it from there. It is a collapsed red clay time then you can measure accurately so you will know more accurately where you may have to cut into the basement floor. If the blockage is tree root growth into the drain the outside access will be much better for getting in a power chopper/rooter device. 

Lastly when you do go to cover the dig back up consider adding an inline access to that part of the pipe for the future or re-access the TEE joint with some gradual turn joints.