The correct answer is 3 months.
The Reserve Bank of India directs banks to treat a cheque, draft, or pay order as valid for only 3 months from its date of issue. Earlier this validity period was 6 months, but RBI reduced it to 3 months in 2012 to reduce the risk of fraud caused by old undated cheques.
If a cheque is presented for payment after 3 months from its date, the bank will treat it as stale and will not process it. The holder then has to ask the issuer for a fresh cheque.