Power of attorney registration

I booked one under construction apartment in Chennai. And the builder has the rights for power of attorney for the land.

I noticed that typographical error in survey no on the immediate mother document, but the patta no is correct.

The old mother documents all are perfect. What will happen for the power of attorney if the mother document rectified

My son who is residing in Australia is buying an Apartment in Bangalore. He has executed one Power of Attorney appointing me (residing in Hyderabad) as Attorney Holder and written his Signature before the Vice Consul of Consulate General of India in Sydney. 

The Builder in Bangalore advised to get the PoA adjudicated

In this connection please advise---

(a)    Distinction between Adjudication and Validation

(b)   Whether Adjudication or Validation, whichever is required, has to be done in Karnataka where property being purchased is located or Andhra Pradesh where Attorney Holder is residing