I am a student doing masters in a university in USA. I am from a Muslim country in Asia. Its my second semester here. In first semester of studies I got financial support from my parents. Now I am supporting my finances on my own. In my first semester my parents paid for my expenses from the money they got from selling a house which they had built taking an interest-based loan. The amount of loan was one third of the total cost of the house. It would not have been possible to build the house without the help of this loan. Last year they sold the house for twice the cost of the house. Is all money that my parents got from sale of house is Haram or a part of it? What is my situation? My parents gave me about half of the amount they had from sale of house. What do you advise me to do?

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

There are many legal rulings related to your question.
1) The transaction carried by your parents is a usurious one and forbidden through Qur'an, Sunnah and consensus of Muslim Scholars.
2) Your parents must repent from that sin, feeling sorry for if and deciding not to return to that sin again. They do not have to do anything else; they are not even obliged to get rid of the whole or part of that amount.
As for the money that you have received it is, Halal for you.
Allah knows best.