Possession

My grandfather have purchased one land 100*40 ft, having three sides government track. On this land there is construction on 60*40 ft and remaining is open play ground. In 1990s my grandfather had given one piece of this land 18*8 (from open ground) to his friend for business on oral agreement, without any rent in good faith. My grandfather had died in 2006 and the person to whom he had given that land also died but his brother is doing business still there. In 2006, after death of my grandfather, internal family problems related to property had started and ended in 2015. Unfortunately my dad has got this piece of land on which that person is still doing business. Now, we want to construct our home but that fellow isnt vacating that place. He don't have any kind of proof that this land belongs to him. Rather, I m paying all the land taxes since our purchase nor he is written as renter on Revision piece of municipal corporation of my town. My father doesn't want to indulge in court activities because it's time consuming but I want to get it back in very short time legally. Please guide me sir.