Possibility of Hard brick with unlocking boot-loader and installing Custom ROM
First of all your phone isn't Hard Bricked.. Hard Brick is something in which you can't go into OS or even in recovery or fastboot. Thats called Hard Bricked Phone.. As from your question, it's just a device specific problem..

Before going into answer, you need to know feww things,

1) Root/Unroot: Rooting and Unrooting are OS specific. Which means you can root or unroot any phone with supported android version.

2) Bootloader: However unlike root/unroot, Bootloader is Device Specific. If you think your bootloader is locked, then you need to find a way to unlock based on your manufacturer or device model. 

2-1) Check If Bootloader is Unlocked :


Open ADB Terminal
Type "adb reboot bootloader"
After it reboots
Type "fastboot oem get-bootinfo"
If it says your bootloader is unlocked you can proceed
To reboot back type "fastboot reboot"


if the info retrieved says your bootloader is locked, then you need to find tools and files to unlock your device specific bootloader.. either your manufacturer released it or any other developer released it.. if you cant find anything.. then im sorry, you can unlock..!

3) Custom Recovery and ROM - as like bootloader, custom recovery and custom rom is depend on your device specific.. you cant flash other devices custom recovery or rom.. you may end up hard bricking your device for real if you did.. so beware..! may be the device's recovery you want flash may have the same chipset, but that doesnt mean it will work on you too..! cause a custom recovery or custom rom doesnt just based on chipset, it also based the device specific configuration and system files..! so beware..!