How to sue for unfair practices by college

I uploaded a video on youtube criticising a hostel policy. I was called by authorities and questioned how dare i did so. I was bashed with foul language and was hustled by authorities. When i tried to answer, they called it misbehaving and removed me from hostel. The matter didn't stop there, they are still holding onto that as a grudge and college Board of discipline is also telling me that either i will be fined or rusticated from the next semester. The choice of charge is defamation of university. If nothing i said was inappropriate and i said it only expressing my freedom of speech. Why am i being held guilty? They have my degree and I don't even know weather i am eligible to file a case against them. I was removed from the hostel and that night I didn't even have a place to stay. There was no notice, nothing. I will share the video link in private text. Also my parents are only supportive to the extent till it doesn't come to my degree. Please guide.