Although your summer placement is based upon your previous academic records, the final placement is more dependent on what you do in the B-school. Standards may be different and vary from student to student but, in terms of good opportunities at these B-schools, even an average student gets a decent internship.
If you work hard enough to be in the top half of the batch, you can definitely expect a good placement offer. Also, academics are not the only field that matters for the placement. There are other various factors at play such as academics, personality, additional skills, passion, and other interpersonal skills.
Many times it’s seen that students with decent academics record trails behind the students with average academics records. So, while getting admission in the B-school don’t overthink about the placement. B- school gives you various opportunities to cross the limits, so do your best. Hard work and dedication can surely defeat average academic records.