So I lost everything on my mobile with the back up files!
Now I googled file extension for TWRP back up, it was .WIN
Even though all TWRP backup files carry the extension .win, they are either tar archives or filesystem images. System, data, cache and .android_secure are backed up as tar archives or gnu-zipped tar archives if compression is enabled. You can rename those .win files to .tar (.tar.gz if compressed) and extract them like a regular archive. Boot and recovery partitions are backed up as .img files using dd.
If someone there can help me, please do! any little info can be useful!