Under s.17 of the Indian Contract Act 1872, mere silence as to facts likely to affect the willingness of a person to enter into a contract is not fraud:

Section 17 of the Indian Contract Act defines fraud as an act committed by a party or by his agent, with intent to deceive another party or to induce him to enter into the agreement, and enumerates five instances, including false suggestion of fact, active concealment, and a promise made without intention to perform. The Explanation to s.17 says that mere silence as to facts likely to affect the willingness of a person to contract is not fraud, unless the circumstances of the case show that it is the duty of the person keeping silence to speak, or that his silence is in itself equivalent to speech. This duty arises in contracts uberrimae fidei such as insurance. Silence is not fraudulent merely because no question was asked.