Dear aspirant hope you are doing well. Seems your question is incomplete or important information is missing from your question. Your profile suggest that you are medicine aspirant. The bond is of two types : bond against Seat and Service bond. Once you are admitted to a medical college, you need to pay an amount of money to leave it. Some bonds require you to serve the institution for a certain time or pay a fine. AFMC has army service bond for 7 years while ESI has it 3 years.

for more details click on the link below.

https://www.careers360.com/question-what-is-bond-system-of-every-college/amp

Thank you