1. this is a very vexed question
2. since the entire purchase consideration was financed by you and your mom was merely a co-applicant in the loan, generally it can be said that for all purposes, you are the sole owner of the property
3. however since your mother's name is also included in the title document, without anything having been stated in it, as to who among the two purchasers paid the full consideration to the seller of the flat or as to the fact that the mother's name is joined as a co-purchaser merely for convenience or as a family arrangement, then in the event you mom dies, then her legal heirs would lay a claim over her 50% share in the flat
4. obviously such a claim as above would be resisted by you and there would be a litigation
5. alternatively if you die, and if your legal heirs [which include your mom, wife and children, if any] claim right in the entire flat, then the mother if she is alive by then, may say that your legal heirs [excluding her] can claim only in respect of your 50% share and not in respect of the entire flat since the other 50% is owned by her. So again there would a dispute
6. obviously upon your demise, your mother's share in the flat would increase since the mother of a male Hindu is also one of his legal heirs as per the Hindu Succession Act
7. however if your mother is not alive at the time of your demise, then your 50% share will go to your widow and children. As to the balance 50% there would be a dispute if the mother's heirs [which include you also] lay a claim over her 50% share
8. so i would suggest that in order to avoid all these complications, and if your mom is willing, then have a gift deed registered for her 50% share in the flat in your favour, so that you become the full owner of the flat
9. however one thing to be kept in mind is that by making such a gift deed, you would in a way accept that your mother was indeed a 50% owner of the property
10. the stamp duty on a gift deed by a mother to son is only Rs 200 and registration fee is also nominal. So that will be the best course for you to avoid any future litigation
11. there is another option of your mom making a Will for her 50% share in your name. But then again such a Will would have to be proved in Court by filing a probate petition and if any heir of your mom, other than you, challenge her Will, then again the matter would get stuck
12. so gift deed is the best option