During loan period without consent of loan provider you can not make any sort of transfer of the property if the property is mortgaged as security.

You can gift it to her by registered gift deed also you can make her nominee of the flat. You can also execute registered will for the same

Execute gift deed.

1. you cannot change the ownership until the loan is outstanding,

2. after clearing the loan, you can transfer by way of a transfer deed,

1) gift deed has to be  executed  duly stamped and registered 

2) you need bank consent for execution of gift deed 

1. See NOC from.bank is required to transfer same vide gift deed to your wife. On repayment of such loan only bank issues a NOC though you can contact bank for NOC and release thereafter a gift deed can be made and registered and stamp duty on same can be paid.

Until you pay back the loan the ownership cannot be transferred. Therefore first pay back thr loan and then transfer the ownership.

You may have to obtain NOC  from the bank from which you have obtained mortgage home loan. 

In fact you may not be allowed to transfer the title to her name during the pendency of home loan,  you may be allowed to do so only after the discharge of entire loan or if purchases the property and undertakes to repay the balance loan amount ad per fresh loan agreement entered with the bank by her. 

You may clarify the details from the bank  who will be the better person to guide you properly in this regard. 

1. Since you are the applicant of the loan and the property is mortgaged with the bank , you can not transfer  the whole share in the flat in your wife's name unless she is also found to be eligible to get loan.

2. In that event you can continue to pay EMI and transfer half share in the falt in your wife's name and that too with the consent of the bank.

3. Otherwise foreclose the loan and gift the flat to your wife.

1. You can execute a proper Stamp Duty paid and Registered Gift Deed, in favor of wife. However for this you will require Loan Transfer NOC from the lending Bank, in name of Wife.

2. AFTER above you may continue paying the Bank EMI's on behalf of your Wife, without any problems.

you can make a claim deed and add you wife name on the property.

Dear Sir,

You first need to explain what you mean by "cheap" here. Do you mean the taxes payable on the transfer. If you wish to save on taxes, then you can transfer the property by way of a gift deed. There are however certain conditions to be met for that.

The cheapest way is transferring the house in the name of your wife is General Power of Attorney.
GPA between blood relations can be registered with stamp duty of Rs.100/- and registration fee of Rs.4/-.
Two witnesses along with identification documents need to be present during presentation of documents.

No stamp duty on transfer of immovable property to wife as gift

The Rajasthan  government has decided to waive off stamp duty on transfer of immovable property from a husband to his wife as a gift, according to an official statement. Till now, one per cent stamp duty was charged on such transfers.
While reviewing the issues related to revenue, Chief Minister Ashok Gehlot took the decision, the statement said.

In case of transfer of immovable property in the name of wife and daughter as a gift, one per cent stamp duty on market value of the property or maximum of Rs 1 lakh (whichever is less) was proposed.
The chief minister decided not to charge stamp duty if immovable property is transferred by husband to wife as a gift, as per the statement.

1. Since the property is under mortgage to the bank you need to seek bank's consent to transfer it to your wife.

2. Bank can give the consent and the loan can get transferred to your wife. If you do not want the loan to be transferred to her then bank will insist on full and final settlement.

You need to approach the bank with a request to permit you to execute a Gift Deed in favour of your spouse. Once the Bank gives your permission, you may execute a Gift Deed and register the same with the Sub-registrar of assurances even though the property is mortgaged with the bank against housing loan.

1. You should first take NOC from bank for transferring the property rights to wife's name.

2. After taking NOC from bank you can execute a Gift deed in favour of your wife and deposit the original Documents with bank as it is already under Mortgage with bank.