Partition among family members

All 3 of you have 1/3 share in property of ur father. 

If ur sister want to release her share then take  registered release deed from her.

Then you  and  your mother can partition property by registered partition deed.

Yes.  You, your mother and your sister have equal rights over the property.  Your sister shall release her rights over her share in the property, then you and your mother can partition the property.

Yes, partition eed could be executed with the sister executing the relinquishment deed. But she only 19. Why the haste?

Thanks for the kind response sir , we have recently brought a property for my sister's future security and needs.

And the land I'm referring to is going to be given for development which in current situation allocated 3 flats for each person . As we bought her separate property we are wishing to have it in our names as Registration charges later for those 3 would be higher.

Could you please let me know which deed is better in this scenario release deed / reliquinshment 

Instead of release/relinquishment deed, you can draw a partition deed dividing the property into  three schedule of properties, i.e., literally dividing the property into two equal pasrts and allotting one part of it  each to you and your mother as A and B schedu;le of properties and the the money given as compenstion as  her share to your sister shall be C schedule of property, and this partition deed may be registered  in order to make it legally valid.