If you've inherited an apartment in Chennai from your father and your mother wishes to gift you her share, you can potentially mortgage the property. However, the process may involve ensuring the property is properly partitioned with your brother, especially if you are Hindu and the property was your father's self-acquired asset. A gift deed from your mother would transfer her share, but a partition deed might be necessary for a bank to sanction a loan solely in your name, or you could consider a joint loan.