There's no application or job portal on their website. They don't revert or acknowledge mails. Who is actually incharge of hiring in the Delhi office?

Reach out to a few head hunters. There are plenty (including on LinkedIn). They have a direct line to HR and they would likely know which teams have a vacancy at SAM.

Bump

BUMP

It is mostly through the headhunters. You’ll find a lot of them on Linkedin. They have direct contacts with the HRs in the firm, who will send your CV to the partners who are looking to hire.