Purchased land & land not hand over after 6 years please advise

Dear Sir Namaskar, My query simple one 6 years back purchased a land 200 Sq yards 70 km from vijayawada near village jayanti at that time property cost Rs 80,000. i was given receipt for the amount but not handed over property after repeat calls & visiting office given 2 checks for the amount after 4 years of payment taking my amount receipt earlier given to me. The 2 checks bounced when asked replied due to urgent payment to others bank balance is nil. Again after repeated queries & visit to his office promised to pay me Rs.2,00,000 as per present govt cost but given in nov-16 only Rs.50,000 rest assured to pay coming months that dosen't happen till now. Now the land cost is Rs 8,000 sq yard. Since working abroad 28/28 days rotation unable to follow up. Recently came to know the seller already had a 420 case on him. Feel cheated, if left this seller running property associates in vijayawada chances others get cheated, expanded his business. please advise how to proceed in this case.