Unauthorized possesion

I bought a land. between my house and neighbour Mr. B. seller has taken loan from  Mr. B in cash.

now i paid more so seller has sell to me that land.

now mr.B encroachment the  land on the basis of ""who holds the stick owns the ox"" that i have given 50 thousand as advance. however no documentry proof of purpose of such loan/advance.

however i paid market rate and got registered with my name. we want to go with legal process to get possession bacause we dont have manpower to fight. They everytime threatning us. 

3 month has passes from date of purchase and mutation is under process, but there as no objection has filed by Mr. B.

please provide a legal solution

thanks