Property Transfer to Legal Heirs

Hi All, my father died in 2013 and he has a property in his name. We have obtained death certificate and legal heir certificate (my mother, me and my elder sister are legal heirs). We haven't transferred the property in our name yet. Property is in Chennai and we are hindus. Have few questions around this: 1. Is name transfer important OR the legal heir certificate is sufficient? The reason am asking is, we are planning to do joint venture or sell off the property in a couple of years, so was wondering if the name transfer needs to be done now/ASAP OR can this wait and be done along with JV/property sale? 2. My sister is US citizen and doesn't have aadhar card in India (she does have a PAN card which was obtained when she was here). Can she be a co-owner in the transfer? What is the special process that needs to be followed, if any? 3. Is there a process like having a primary owner (like first holder in FD) as my mother and having me and my sister as co-owners/secondary owners/joint owners? The reason for asking this is, the rent/income from property can tagged to the first owner like we do in FDs? 4. I know me and my sister can sign a release deed and get the property registered on my mothers name. But if we do, then again we will have to do these processes after my mother's time. Is there anything like she owns it now and after her time, it comes to co-owners? Thanks a lot for your support/guidance.