Sale Deed Before Section 4, Mutation Application Before Section 4

I Had Purchased land in year May 2010, I Had instantly applied for Mutation along with necessary documents. In the year 2013 mid I came to know that my Mutation Application was rejected by citing a prohibitory letter. I was under impression that property is mutated till i obtained the 7/12 for further development. I had registered property after taking all the necesary steps as known to me, like search report, K Prat etc. the total area of property was 2.95 Hr. Now, Land acquisition officer suggests that Registered Sale Deed was not valid, and have advised registrar to Cancell the same. Want to Know whether: 1) Registrar has power to cancel, what should be my action plan? 2) I had acted in good faith (Actually) and had got search report which stated that property was transferable and not subject to any acquisition only then i proceeded with transaction? want to know my status? 3) Section 4 has come / Published in the month of February 2013 that 3 years after the land was purchased through Sale Deed. Can Property Purhcased before Section 4 be subjected to Cancellation 4) On Exploring more about the problem, i came to Know that section 11 ( was not applicable for agri lands below 8 acres and also there was a general permission granted by Collector about sale purchase of such lands for which no specific permission was to be sought from him. Seller had attached affidavit in sale deed that the land is below 8 acres and not subject to acquisition as of that date. 5) I need advise about action plan. I am taking help of a Lawyer here but second opinion shall be of help.