1. Property belongs to:
a) Wife : 50% share
b) Wife's Father: 50% share

2. Wife can execute a Gift Deed for her 16.66% to her Husband

3. Wife's Father can execute a Gift Deed for his 16.66% to his Son-in-Law

4. AFTER above:
a) Wife : 33.33% share
b) Wife's Father: 33.33% share
c) Husband: 33.33 share

5. Since property is already under Bank Mortgage, FIRST take Bank NOC for point no. 2 and 3, and give undertaking that all the three persons shall be liable for repayment of Bank Loan.

You need bank consent to add  name of husband  as co owner during currency of bank loan 

To add the co-owner now you need to take bank noc and make him a couple owner. Other wise you can  have a separate agreement with him registered that once the payment of emi will be done he will acquire 50 percent Co-ownership in the same. The said agreement will be a tripartite agreement between you, father and husband. 

1. The flat is presently co-owned by the wife and her father and the property has been mortgaged with a Bank from where the wife or her father  had taken housing loan.

2. Mortgaged property can not be dealt with without the written consent of the lending bank for which not gift deed in favour of the husband can be registered by the wife or her father during the pendency of the said loan.

3. The wife and her father along with the husband can apply to the Bank for adding him as the co-applicant of the said loan and also for giving consent to th wife and her father for registering a gift deed gifting a part of the said property in favour of the husband on condition that the said original gift deed also will be kept in deposit by the Bank.

4. The Bank should not have any objecytion  since in the said process one co-borrower cum guarantor cum mortgagor will be added to the said housing loan making it more secured.  

See you need a NOC of the bank after same only the ownership can be changed or transferred. See husband can enter into sale agreement for the share in the flat and can pay EMI, once same is done the ownership needs to be transferred. 

You need to draft the same with help of lawyer. Contact me through kaanoon.My contact is 9a7g6g9g4e9i0f9f1a1

Gift deed can be executed by you in husband favour to give him 50 per cent share in property 

2) no such termination clause can be added in gift deed 

Sale Agreement can be made for 50 percent of  the ownership of the flat.

See marriage cannot be ground if he is paying for EMI and sale agreement is made then no such condition of marriage can be there in the agreement. 

If sale deed is already registered then no one can be added as co owner anymore.

However the husband can be made a co sharer of it by transferring a share of it in his name by a registered gift deed.  

At this point of time wait tripartite agreement has already been made between the parties bank and the Builder it may not be able to be changed but at the time of registration if your father relinquishes his right and transfer the property to him then it is possible that the registration can be done in his name  an you can contribute EMI after agreement between both the parties.

 otherwise you need to speak to the Builder to transfer the entire property between the names of you too and you need to apply a fresh loan with Tripathi agreement between you builder and the bank as this is home loan you can pay from the proceed of the new loan to close old without penalty.

Please note that the EMI will be taken from only one bank account not by two bank account in any case

Father can execute gift deed of his share to husband. Not advisable to pay EMI without gift deed.

Without executing gift deed or settlement deed, ownership will not transfer. Whatever the agreement execute, registration of GD/SD is must to acquire ownership.

Termination clause is valid but than have repercussion.

1. You can execute an agreement on a Rs.10 stamp paper  detailing all the conditions and then register the same.

2. The Agreement should also mention that in case of divorce or separation with you, the said Agreement will ceased to have any legal effect.

You Required bank consent to add name during loan.

You can execute gift deed But you cannot mention such clause in agreement .

Both the suggestions are not legally valid.

Firstly he cannot be added as another joint owner of the property without a portion of property is transferred to his name by a registered deed.

This can happen only when the entire loan amount is discharged and the title documents are received by the borrower with no due certificate .

Secondly, until he is not a co-applicant to the home loan, he may not be permitted to pay the EMI amount.

The alternative is that he can pay the said amount to his wife's name with an unregistered agreement entgered between both,  stating that he will continue to transfer the EMI amount every  month to her bank account and she shall transfer a share in the property to him by executing a registered sale deed in his favor or shall return the entire amount received from him towards EMI loan repayment so far with interest after the loan is fully discharged.

Your subsequent question has been answered in my previous post itself, you may go through that once again.

1. It will not be possible to add co-owner name of husband without permission of bank till the property is mortgaged with bank

2. But it can be done if bank give permission to transfer ownership from father to husband of coborrower.

3. If bank doesnt give permission then agreement can be made for payment of EMI's and share in ownership of property once the loan is cleared.

As long as the loan is being paid the ownership of the property cannot be transferred. He may give the EMI but that is a different matter.

A separate agreement can be made with the husband and he can become a co owner after paying for 50 per cent of the money. This i am afraid cannot be added.