Your poor academic record can be a major hindrance, especially in summer placements because the companies know you haven’t done anything major yet in the B School. So I will suggest you some tips that might help you compensate for your low 12th class marks and get you a good internship offer

• Enroll in an online course as this might be a major topic of discussion in the interview. It should preferably be an advanced version of your current course or a unique course.
• Get involved in volunteer work at NGOs. This will not only prove to be beneficial during your interview but also will help you become a part of social service committees on campus.
• Master a new language preferably French, Mandarin or Spanish as this may increase your chances of getting International placement or foreign exchange.
• Look for internships that offer practical knowledge for a short period of time.

As far as the Final Placements are concerned, you will have to improve your profile to attract the best recruiters. Some tips to improve your general profile are

• Rather than focusing on your past academics, focus on the new phase of your life and give your best
• Go for courses that offer live projects as recruiters highly prefer such exposure. Sometimes even the on-campus committees offer such live projects. Many times the winners of such projects get amazing PPOs or cash prizes.
• Joining a good on-campus committee is beneficial not only in maintaining a good campus life but also improving your overall profile. You get amazing exposure by interacting with industry professionals in the corporate world during events and conferences.
• If you are skilled at writing, do the same for business magazines or websites.

All this will help you make the most out of your MBA experience and also improve your profile enough to attract the best placement offers. The only key is to work hard relentlessly.