There is no legal bar to your wife and mother in law being witnesses to the will 

Any one can be witness to the WILL but it is advisable beneficiers should not be witness.

Dear sir,

There is no such rule prohibiting your wife or mother-in-law from signing as witnesses to the will. Thank you,

As long as they both are not the named beneficiaries of the property bequeathed in the Will, their attesting witness signatures are very much legally valid. 

Except the beneficiaries any person can be attest a will as witness, including wife mil. More so, they are very proper witnesses. Proceed with execution of will. No registrar is mandatory but if you want to register, no stamp duty is chargeable on registration  of will. You can also deposit the will in sealed cover with the Registrar. There is provision for that under law.

-  As per law, anyone can be a witness to the signing of a WILL , if he is an adult , and not a blind , and further must not be a beneficiary. 

- Further, the said witness should not be a close relative, such as a spouse of a beneficiary

- Hence, your wife cannot be a witness , but mother in law can sign the same. 

Hello,

1. No, there is no law that prohibits your wife form signing as a witness of the Will by your father. in fact any adult person in sound min d can sign as a witness. Being a relative or interested party does not bar the person from being eligible to sign as a witness.
2. The role of the witness at a later stage is only to testify that the person signed the Will in their presence and there has been no foul play. 

Hi, There is no rules such that wife and mother in law will not become a witness. However, If your sister is alleged that will is fraud  and it is obtained by undue influence then it is difficult to prove the same in the Court. It is better and safer you can take a signature of some  other person.

They can sign as witness provided if the property is not registered only in you name as your sister may object in future that you misled your father.

G.Rajaganapathy

High Court of Madras  

They can but it's better to have some independent witness in the same for transparency. It needs to be registered

There are no rules as such however it is advisable to keep any other family relative as a witness or even an Advocate to sign for the Will.