I think he is hiding his id just because, he dont want 2 tell Indira and her family that he is rich and he doesn't want to be with his family also a brother like sameer 😡 (he cant even touch his brother, he have to behave like a stranger) and also Natasha, who's always behind him
the same time I dont think Rishi is the reason for vidith "death or jail or ..." maybe he know about vidith. he doesn't want 2 tell the truth 2 Indira cos she like her brother a lot