RBI Clarence for mutations of the inheritance properties by the persons of Indian origin( POI)

My maternal Grandfather purchased (2) properties in Kolkata & Midnapore ,Westbengal in the year 1960 & 1957 respectively and died intestate on 13/09/1976 leaving behind 3 Sons & 5 Daughters who are the legal heirs and successors by way of inheritance/succession .Out of the above 3 sons ,one of his son who settled in USA along with his families, predeceased him on 05/12/1979 leaving behind his wife & two daughters who are the legal heirs & successors by way of inheritance/Successors of their Father in law & Grandfather and became the lawful owners of 1/8th joint share. As 3 of the above persons permanently settled in USA since last 45 years , They have appointed one of our relative in India as special power of Attorney (Routed through Indian Embassy, Newyork, USA))to do all the formalities . After submissions of all the papers in Block Land Records Office in Kolkata ,they have raised an objection that A clearance from RBI is required and raised the query to Reserve Bank of India,Kolkata Please let me know whether any RBI clearance is required or not to get the mutation in their names who are the PERSONS OF INDIAN ORIGIN. They have also send another consent that their 1/8th share will be given to the rest 7 persons who are in India hence their is no remittance of money to be sent to USA in their account. For your kind information BLRO office done the mutation in case of 7 persons or their legal heirs staying in India except the USA POI persons. Waiting for your reply. Please help me to settle the