In a long Facebook post, Amaal criticised Sonakshi for unnecessarily "targeting" his brother saying the whole debate started when singer Kailash Kher expressed his views on actors turning singers.
"Armaan Malik only retweeted him (Kailash) saying it's a sad state and musicians should be given the platform, and he did not tag or personally attack Sonakshi.
"What my mind fails to comprehend is why she is targeting Armaan alone, because obviously it's easier to call him insecure than calling a senior Hindustani classical singer that," Amaal wrote.
"... There's nothing wrong in asking for one (a better artiste), we aren't talking about ourselves. I'm sure we are a country with amazing musical prowess and I repeat, they must get a chance to showcase it on a stage like that," he said.
Amaal also took pot-shots at Sonakshi's brother Luv Sinha, who accused him for "stealing tunes", by calling him "an uncouth idiot trying to get some desperate fame on a social platform".