Release deed clarification

Hi All,

I need one help for release deed. Me and my borhter want to release the rights of two flats to each other.

Property Descripttion as follows

1) 1 BHK on the name of Father and Mother ( Both are expired).

2) 2 BHK Flat on the name of my mother(Expired), me and bother.

Can we make release deed with nominal amount by registring release deed or need to pay registration charges for releasing property to each other.\

Thanks in advance for your suggestions.

Pankaj.