I will be completing my BCA this june. I want to go political Science hons, should I go Bachelors in p s, suggest some colleges in Delhi.

I would suggest you to rethink on your decision. What makes you interested in Political Science after BCA. I feel, you should think about getting employable rather than getting qualifications. Still if you wish to diversify, then go for M.A. Political Science directly based on BCA.