Property Belongs To Whom?

My father-in-law's brother passed away few years back. He has 3 children all married, 1 son and 2 daughters. His wife is alive.
He purchased land 300 sq yards for house but all the expenses for the construction of the house were taken up by his son. The sale deed is in my FIL's brother's name. He did not transfer it on his son's name.
Now, whom does the house belong to?

 

No, he has not left any will.
Its been a year. Since last one year aunty has been moving between her children. She stayed for 3 months with her daughter in India, then went to US, stayed in her son and other daughter's house for 6 months. Returned and is now with her daughter in India. The house is a double storeyed one. Aunty wants to now return to her house. So, the daughter in India is saying she will move into that house along with her family. Her husband is fine with that. Since house is double storeyed they want to make some changes to the house so the upstairs becomes and independent flat. That way they can take care of mother as she will be near to them and same time have their space, privacy too. And give their present apartment on rent. But, the son is saying since he spent all his savings and constructed the house so it rightfully belongs to him. And, he cannot give that right on the property to his sibling. He says he will buy a separate apartment for his mother near to his sister's present apartment so that she can look after her but not allow any remodeling of the house.

 

My father- in- law has advised them to sit together and discuss and sort it out. The daughters are willing for the sake of their mother but son and daughter- in- law are unwilling. Son has already told them never to raise that topic with him. Their mother is tired of moving house to house between her children. She wants to go back to her house, hire a full time maid and live on her own. Daughters don't want the mother to live alone on her own. My FIL is also holding himself from suggesting to the daugthers to go the legal route fearing the family reputation getting tarnished in society.

 

We also don't want my inlaws to get into this. They are also old and get worked up emotionally over this everytime. If we advise my FIL to suggest to them the legal way and get over this, I want to know what will happen, what would be the outcome.

 

I really doubt the son will give the daughters their shares as per what my FIL could judge the attitude of the son. The daughter in law also thinks that the daughters are trying to grab their property. My FIL says his brother when alive never mentioned that the house should be in son's name. The son bought a house in US and settled, so the father feared what would happen to his wife after him. He infact always used to ask his daughter and son-in-law who is in India to give up her apartment on rent and come stay with them as they were living alone in that huge house. That way they would also save up some money too. But,the daughter never did that fearing what people would think. Now since her mother would be alone she wants to do that but only after remodeling the house and making upstairs independent.

 

Can someone tell legally, whom does the whole property ie., Land+House belong to if the father did not transfer it on son's name? Does it automatically go to son since the son spent money in construction of the house?