What to do if you are being forced to marry someone?

Run away from that old caste crap.

You are FROM South Asia but where are you now?  Most countries abhor forced marriages.  You do NOT have to follow your parent's wishes.  You should consider their advice but they also are supposed to consider your feelings.  You need to be a part of where you are now.

I really think this is ridiculous -- your father didn't have any trouble marrying someone from a lower caste, did he? -- but if it really matters to you, talk to members of your father's family and ask for their help finding a suitable match.

If "caste" is your major concern, I cannot advise you. It depends upon how your society and culture work . But if you don't want to marry someone, there are ways to avoid it, such as leaving the area, or even the country. But you will also pay a price by alienating your family. Good luck.  

Since your father married someone of 

lower caste, why would it bad for YOU 

to do so? You sound self-centered, 

conceited, and immature. 

this is your life not your mothers, was your mothers marriage to your dad an arranged marriage?if it was an arranged marriage then ask her how she liked marring a man she didn't love. Men who are stuck in arranged marriage have affairs I know that's something you don't want to hear or even believe. Thats why men get away with cheating,the wife doesn't believe he would do that to her and he knows this and uses that by saying these words, NOW YOU KNOW I LOVE YOU I WOULD NEVER DO THAT TO YOU. 

They cannot force you unless you allow it. Legally you are permitted to refuse. If you're threatened, seek help from someone in social services.

That is a problem but people have point blank refused and that has worked. It has caused shunning but don't marry someone if you think it's wrong.