Need guidance on purchasing land

Hi , My name is. I want to buy one property in my home town. pls, clear the property is problem or not. total four parties .I am the fourth. the first party has 5 brothers. but the three brothers sold their land ( their part- not in paper ) without the sign of balance brothers. the second party bought and the second party sold to the third party. now the third party ready to sell the land for me. pls confirm the land is ok . or the problem will come in future . is there any remedies to solve the issue. the first party sold their land five years before.