Hi Mahesh,
can you take a picture that shows the error message?
Or do you need the BitLocker recovery key after repairing your mobo?
Than take a look at Where to look for your BitLocker recovery key
If that doesn't help and you have no chance to get your BitLocker recovery key, the only way i see, is to clean the disk an reinstall Windows. But let me say, that in that case you can loose the recovery partition, too.
Maybe try to boot gparted live disk an delete only the windows partition. After that try to boot the factory os recovery menu and reinstall windows as it was at the time of bying the device.
Best regards
Daniel
