Cash gift from parents

you have to made a gift deed prior to taken a credit in bank account. one witness is fine.

Parents give gift to their kids out of natural love and affection. Though no document is strictly required but since its a cash gift you may better take a simple letter from the parent stating the fact and mention of the source of income and parent PAN. It is sufficient if is written that the gift was given out of declared source of income and out of natural love and affection.