Should there be a comma after "Singh"?

Yes.

Thanks, hightor.

Thanks. I was too unsure to even make a guess

I know – I sympathize with anyone trying to learn the language! Here's how I made my guess:

1. Iswaran's defence lawyer, Senior Counsel Davinder Singh, then confirmed that his client would be pleading guilty.

2. Senior Counsel Davinder Singh, Iswaran's defence lawyer, then confirmed that his client would be pleading guilty.

There's a natural pause that calls for the commas before and after the enclosed phrase.

But leave that phrase out and there's no pause.

1. Iswaran's defence lawyer then confirmed that his client would be pleading guilty.

2. Senior Counsel Davinder Singh then confirmed that his client would be pleading guilty.