Can a co-owner of flat be a single owner in new purchase

Hi All CA's and Expert financial/Legal advisors,

Presently I am the co-owner(Joint) of a a  flat in CHS since 2008. My uncle's name is first in the sale agreement and mine is second. There is no mention of percantage of ownership in the agreement. We are planning to sell this flat and Immediately  purchase a new property.  Now, below are my queries regaring the sale of property :

1. Can I be the single owner in the agreement for the newly purchased flat?
2. I would be availing an additionalhome loan (10-15 lacs) in buying the new flat. So the gain from current sale of property plus my home loan (10%) would be the pruchase price of new flat. What would be the tax implications on the same if :

• A. I purchase the ONLY in my name 
• B, I purchase the new flat again in the same order of names, i.e. My unclae names as first owner and mine as second.

Please note that my uncle is not having any Income and also he has not filed any Tax returns for few years.

Would appreciate if any one can guide on my above queries.