I took Computer science in my 12 standard so is it safe to opt biotechnology for further studies?
Yes if you have an interest in Biotechnology, if you know biology well, then definitely you should choose biotechnology. In some colleges it is compulsory to have biology in 12th class for pursuing with biotechnology. If you fulfill that criteria then all is good. Otherwise do some research on the key points of what is taught in biotechnology and see for yourself if that interests you or not. Then it will be a lot easier for you to make any decision.
Regards.