Hi
1) In general any property in the ownership or possession of a woman is her absolute property by virtue of Section 14 of Hindu succession Act.
2) As such your mother can execute a registered gift deed in your favour and you can mutate the property in municipal records, Electricity office and thereafter obtain property tax, electricity bills etc in your name. All the more if you clear of the existing loan and then ask your mother to execute a gift deed in your favour, this is the best option as you have a clear title (an act of clearing loan in the name of your mother gives you the natural right to your mother's love and affection).
3) If you do not intend to avail any bank loan on the said property (either by way of continuation of existing bank loan or any financial requirements in the next 2 years, then the execution of registered gift deed by your mother in your favour is the best option.
4) A Registered Gift deed once executed cannot be revoked/ cancelled by your mother without following the due process of law. In general, once the Registered Gift Deed is executed, the Donor or your siblings cannot have any claims whatsoever.
5) However since
i) there is an already existing bank loan and
ii) also if you intend to continue the existing bank loan or obtain a new loan on this property in the next two years and
iii) also given that your brother who opted to be the second applicant for the purpose of bank loan and then backed out from paying the installments can still make a claim at a later date, the following steps are advised:
a) Since the property is already mortgaged to the bank, your mother can transfer the property to your name either by sale/gift deed only after obtaining a No Objection certificate from the bank especially during the subsistence of the loan.
b) So you should first get the bank to permit you to be included as a second applicant for the loan in place of your brother which i am sure on the fact that you have repaid most of the loan, bank's will be more than willing to add you as a second applicant.
c) In the circumstances stated by you , A sale deed by your mother in your favour is preferred over the Gift deed (given that there are other siblings who are likely to challenge at a later date) as banks in general will prefer to extend loans readily to a sale deed.
d) It is a normal practice for banks to grant loans against Properties obtained through Gift deed only after a period of 6 -12 months as there is no sale consideration in a Gift deed.
e) You should also consider the fact that Banks in general will not extend home loans for properties obtained as a Gift(through Gift deed) and instead will grant loans in the form of "Loan against property" (It has shorter tenure of repayment, higher interest rate and no tax benefits like home loan).
Hope this information is useful.