Thanks for the quick one ! But i am new to rooting .. Could you please point me to a resource ?
Update : Flashed Gapps as well as the custom rom again .. Both didn't work
Update2 : installed Fx camera and another gallery app from play . Both work fine ..
And i believe out of curiosity i would have deleted .nomedia file from some other place also other than sdcard
Did that caused that problem ? If so where i should add that file ?
Update3:
Was searching forums then found it .. My mistake app was in a disabled state and all disabled apps listed @ bottom
If you go into Settings > Apps > All, and scroll to the very bottom, is Gallery disabled/grayed out? You can re-enable it from there.
Thanks dmmacrk for solution to mp3 indexing