Designing Kitchens and Bathrooms - Granite Counter with Stainless Sink

Is there any problem with installing a drop-in Stainless Sink in a Granite Countertop?

I took the sink out of the old laminate countertop and would like to reuse it if possible.

What is the standard method of supporting an undermount sink?

I don't see any reason you couldn't reuse the existing sink, but you will need to provide a template to the granite installers so they can make an accurate cutout.
If you decide on an undermount (IMO a great choice, easy cleanup, good looks) you can purchase an undermount kit. The sink rests on suports provided in the kit and the countertop is installed. Then the sink height is adjusted to meet the countertop. Caulking provides a water tight seal.
Or the granite installer might just use 2X4s.

I just went through the same ordeal but decided to go with a new Kohler undermount for looks and easy cleaning anything on the counter can easily be moved into the sink without the lip of a surface mounted sink in the way. Just a thought!

Undermount sinks are wonderful. A new granite countertop deserves a new sink and possibly a new look.