After a car accident

I had a road accident on 3rd April near Kanchipuram (Tamil Nadu). I was driving my car on a highway and all of a sudden one bike (riding 3 people) came in front of my car without giving any prior signal. I tried to stop my car by applying full brake and first i hit on the divider and then the bike. Out of 3 person on the bike, 1 person was injured and they took them to the Govt. hospital. I went to the nearest police station and told the officer about the incident. I was scared as i don't know the local language and i thought to go to the police station to avoid any disturbance from the local crowd. Then one SI from that police station went with me to the hospital to see the injured person. I had a talk with them and we both agree to settle the issue without registering any FIR/complaint to police. The SI also suggested if we both can settle then no case will be filed and the SI told the other party that police will not entertain/accept any FIR if we go with this settlement. As part of the settlement, the other party had written the details in a paper, addressed to me, and 3 witnesses signed the paper including the injured persons. After that, the SI requested to take both the parties to take one copy of that statement and police also kept one copy. After 2 days, one person called me and told me that they admitted the injured person in private hospital, and medical expenses might be around 3 lacs ruppes. Though they didn't ask me for any amount or so, but my question is: What can they do now? what type of precaution/steps i should take from my end? or should i wait till they take any action?