Dear Student,
First of all I need to inform you that 71% is not such unpleasant percentage it might not be very good but it is cannot bad be stated as bad either. Your 12th marks are just a mere aspect to decide your career there are many other major aspects than it also. Many people I personally know with marks below such gaining huge success just by their hard work and studying the subject they had passion for and you can easily get a good college which has admissions on the basis of entrance or interview for any course you want to pursue. But following are some courses you might consider being from PCM stream:-

• Engineering is one of the sought after career by science students
• Architecture. Bachelor of Architecture (B. Arch)  Five years course
• Merchant Navy
• Commercial Pilot
• Bachelor of Science(Bsc.)
• National Defense Services-Indian Navy Officer, Indian Air Force
• Railway Apprentice Exam
• B.A or bsc in Arts and Humanities
• You can also go for CA or B.com or B.com hons or BBA if you wish to.

Hope this might help you.