Bangalore Land Layout Survey Issue / Land Grabbing

My father bought a land in September 2013. The seller is a local party living in Bangalore and handed over all the documents to us including A Khata, Ownership transfer documents, receipts for betterment charges etc., Except one document in original which is the layout showing the exact site. The seller's broker and the seller gave a COPY of the layout which showed the partition of 3 plots (e.g.: 1,2,3) as part of the survey number 6/1. It had a notary seal on it. Our land is 2 in between 1 and 3. Before purchasing, we've consulted a local attorney to have the legal opinion. The attorney reviewed the papers and suggested to publish an advertisement on the local paper stating that this land has been owned by 4 parties in the past excluding us and advised to contact us if there is any claim in ownership of the property. We've placed the advertisement and waited 2 weeks and since there was no claim from anyone, we decided to purchase the land. Also, we didn't do any survey. Within a month of purchase, a local goon demolished our compound (2) and adjacent plot's compound (3) The goon is claiming that 75% of lands 2 and 3 are coming under the survey no: 6/2 under which his big land (3+ acres) is included. This guy is a famous local goon and a real estate mafia as told by the people around that area. The lands 1,2 and 3 are tagged as part of survey no: 6/1 as per the layout and Khata papers. BBMP website shows the proper taxes paid by previous owners and current owners as my father. We've requested the govt. surveyor to measure all the lands under survey no. 6/1. The govt. surveyor has not measured survey no. 6/1 (because he said few other lands part of 6/1 have buildings constructed) Instead, he measured the goon's survey no. 6/2 land and marked the dots favoring the goon. Looks like, he was bribed as well. The govt. panchayat surveyor has prepared the report stating that same favoring the goon. and it indicates that 75% of land 2 and 3 are part of Survey no.6/2 and not 6/1 as in the documents. Ultimately, the motive is to grab our land (2) and the adjacent land (3). However, we are suspicious about the broker and seller whether they have forged the layout document marking 1,2,3 with just the notary. Note: The seller was a GPA holder and his brother was the owner of the land 2. The seller (GPA) has signed the sale deed and agreed that he received Rs.XXX in cash and if there is any litigation he is responsible to clear that issue. We are able to contact the seller but few times, he said that he is not responsible for this issue and we have to deal with his brother who is an NRI in Dubai. This showed lack of accountability and rip off. Possibilities: 1. The goon may be correct? 2. How does the Govt. give A Khata for such a property and ownerships have changed in the past successfully? Should we contest the govt.? 3. Seller might have forged layout document and cheated us? Questions: 1. What are the possibilities to claim the land? 2. Can we file a criminal complaint against the seller and try to get the money back? Please advise. Thanks We need legal help.