Correction Deed

I had purchased a commercial property in Bahadurgarh in Haryana. All documentation, payments, sales deed and registry happened as unit no 9. On the other side, builder when launched the project, developed 12 shops and provide the serial number to each shop as 1 to 12. Due to some reasons, builder collapsed shop no 1 & 2 and remain the serial number for other shops (3 to 12) as it is. Shop owners of unit number 1 & 2 were compensated by builder separately. After 18 months of the registry, builders is asking for correction deed and change the shop no from unit 9 to unit 7. Builder is giving fresh number to all remaining 10 shops from 1 to 10. Which means every shop will be given new unit number which is less than 2 as original unit number. Means shop number 3 will be know as 1 and shop number 12 will be known as shop 10 and like so. Builder is bearing all the legal charges in this regards and said this is normal practice in property cases. I have two queries now: (A) Is there any harm if correction deed happened because all previous communications and documentations happened in the name of unit no 9 ? (B) If this is normal case, What precautions I should take and what are all documents I should ask the builder to give me in support of this correction deed so that I should not have any problem in future while sale/ purchase and renting agreement with any private and government agency. Please note that builder is terming this as "Typographical" error in correction deed Thanks