Co-owner selling plot with gpa from other owner

Hi,

    I am planning to buy a plot in Bangalore. The seller is in US. The seller and his wife are co-owners of the plot.

    The seller has mentioned that only he can be present in India for transfer. His wife will not be able to come to India.

    The seller is planning to create a GPA from his wife to him and notarize in the Indian embassy in US.

    Is this transaction valid?

    How risky is the transaction if only one co-owner is present with a GPA for the other owner, that is created outside India?

    Do you recommend that I go ahead with this transaction?

Thanks,

Dileep Ramesh