Indian Kanoon- IPC Section 102
Commencement and continuance of the right of private defence of the body.

The right of private defence of property extends, under the restrictions mentioned in section 99, to the voluntary causing of death or of any other harm to the wrong-doer, if the offence, the committing of which, or the attempting to commit which, occasions the exercise of the right, be an offence of any of the descriptions hereinafter enumerated, namely:- First.-Robbery; Secondly.-House-breaking by night; Thirdly.-Mischief by fire committed on any building, tent or vessel, which building, tent or vessel is used as a human dwelling, or as a place for the custody of property; Fourthly.-Theft, mischief, or house-trespass, under such circumstances as may reasonably cause apprehension that death or grievous hurt will be the consequence, if such right of private defence is not exercised.

If the offence, the committing of which, or the attempting to commit which occasions the exercise of the right of private defence, be theft, mischief, or criminal trespass, not of any of the descriptions enumerated in the last preceding section, that right does not extend to the voluntary causing of death, but does extend, subject to the restrictions mentioned in section 99, to the voluntary causing to the wrong-doer of any harm other than death.

The right of private defence of property commences when a reasonable apprehension of danger to the property commences. The right of private defence of property against theft continues till the offender has effected his retreat with the property or either the assistance of the public authorities is obtained, or the property has been recovered. The right of private defence of property against robbery continues as long as the offender causes or attempts to cause to anyperson death or hurt or wrongful restraint or as long as the fear of instant death or of instant hurt or of instant personal restraint continues. The right of private defence of property against criminal trespass or mischief continues as long as the offender continues in the commission of criminal trespass or mischief. The right of private defence of property against house-breaking by night continues as long as the house-trespass which has been begun by such house-breaking continues.

If in the exercise of the right of private defence against an assault which reasonably causes the apprehension of death, the defender be so situated that he cannot effectually exercise that right without risk of harm to an innocent person, his right of private defence extends to the running of that risk.