If the complainant got a simple injury and no weapon was used, the offence shall be bailable one and in case you are arrested Police shall release you on a personal bond. There is no need in such a case to go for AB. The police might not register FIR at belated stage.
You can file an application for anticipatory bail even if a FIR is not registered. The court my dismiss the bail application but may pass an order to not to arrest in the event of a FIR to be registered at a later date.
1. You can not file an application for AB before the FIR is filed,
2. In your petition for AB, you shall have to mention the FIR Number and also the police station where the said FIR has been filed,
3. After filing the AB petition, the case diary will be called by the Court and if there is no FIR filed, there will be no case diary,
4. Hence, no application seeking AB can be filed without mentioning the FIR number.