Section 40 of BNS : Section 40: Commencement and continuance of right of private defence of body.

Explanation using Example

Example 1:

Ravi is walking home late at night when he notices a group of men following him. They start making threatening gestures and one of them pulls out a knife. Ravi, fearing for his safety, picks up a nearby stick to defend himself. Even though the men have not yet attacked him, Ravi's right of private defence of the body has commenced because he has a reasonable apprehension of danger to his body. This right continues as long as the threat persists.

Example 2:

Meera is at a crowded market when she sees a man trying to snatch her purse. She yells for help, but the man continues to approach her aggressively. Meera, feeling threatened, uses her pepper spray to fend off the attacker. Although the man has not yet succeeded in taking her purse, Meera's right of private defence of the body has commenced because she reasonably fears for her safety. This right continues as long as the threat of the attack remains.