Regarding a use of comma.

Use of the comma within that instance, is parenthetical:

Sentence: ""This is Raj, whom I'm told, defended his case brilliantly on a TV channel.

Note the usage of the word whom in place of 'who''.

Thanks

sorry, I was a bit hsasty,

Sentence: "This is Raj whom, I'm told, defended his case brilliantly on a TV channel."

Sorry, I erred. The parenthetical phrase consits of "I'm told."
Proof of that would be to write the sentence without that phrase:

Pronoun. The original sentence had the right pronoun--who. Whom is wrong. "Who," the subjective pronoun, is the subject of the rest of the sentence after the parenthetical phrase--"who defended his case ..."

Roberta is right. After looking at a few more times, follow her advice.

See, even those who speak the language, and at one time were professional communicators, mess that up, too.

Trust me. I would answer more questions if I had more answers.

Ask not for whom the bell tolls..."