Interesting. This is what I received back from my Diamond Concierge

Here is what they offer:
Greetings from Park Hyatt Chennai.

The following would be the DIAM benefits :-

· Upgrade to our View category on a complimentary basis

· VIP amenities in the room

· 1000 bonus points

· Late checkout until 1600 hrs

and from an earlier email:

Good Morning,

I am sorry this hotel does not offer complimentary shuttle service to/from hotel or local transportation.

All good info - if someone stumbles on this thread in the future hopefully they will contact the hotel directly to confirm, and hopefully the benefit will be available to them.