Encroached Land - Houses are being built

I need an advice pertaining to a situation . I am explaining the points in accordance with the chronology. 1. In my village i have a land of 3 Acres of agri land with joint settlement patta for 6 people which is not gone for subdivision. 2. SInce the land was not used for cultivation and no machinery that time we couldn't make it ready for use. 3. Since my father passed away and he has been saying about this to be measured and clarified from revenue, i started digging and got it measured the land 3 months ago. 4. To my surprise, the land had been encroached by Ex sarpanch of our village and sold for residential plots saying that it's a poramboku land (govt land). 5. once i had the land measured, by then people are in the process of constructing houses and some plots are vacant. 6. SInce people who are building houses are from my village i wanted to go to them with proper discussion and solve issue amicably. 7. They were ready to discuss and almost came to point where in they will pay about 10% valuation for which i was OK and suddenly overnight they took u turn and went to local leaders and MRO with petition. 8. I did not object for the construction and asked them not to proceed with any new constructions till matter settles in vacant plots thus some of houses were constructed by 70% in last 3 months. 9. People who bought lands there does not have any valid support document that proves ownership and they just got a stamp paper signed by person who sold plots without any survey number etc. 10. MRO who had come for inspection asked me to go for sub division and then only they can help me finding my piece of land over Joint Patta and not to object house construction and also he recommended go to court for legal proceedings if needed. 11. To continue my family legacy i wanted to go things peacefully and did not wanted to go legally earlier. 12. Because of recent developments i would like to take legal route and would require any help with laws and possible ways to take it. PS: I have a Zameendar patta on this land and also other pattadars are enjoying their portion well enough. Appreciate any suggestions in this regards to proceed further.