If you have not already, please do some web research on cultural differences and sensitivity with Indian culture. I'm sure there are books available as well to give you a general overview. I am certain, too, that in SF you have access to many Indian-born colleagues within your organization or with customers, partners, affiliates, etc., and I'd ask some of them for a few words on the right way to approach your Delhi-based team members.
Questions you'll wish to explore include how to give permission to speak freely, whether you will need to read between the lines of the spoken word to get to the unspoken sentiments or if your team will feel culturally comfortable with honest feedback about you and the work, and how to structure the conversation - i.e., whether to start on social topics and move to business (and how to make that transition), or if you will be expected to just jump right in since you're the boss/visitor.
To "understand their work context," is there anything you can do while still in the States? If you're not directing their work, who is, and what tasks are they being given in addition to whatever you might assign? If you mean the context of their life outside of the work they do, you may be getting onto tricky ground, since cultural assumptions about work/life balance, value of money vs. respect, collaborative vs. individual work-styles may all be part of that conversation. Ask your local Indian SME's how they or their friends would like to see these matters sensitively raised. And good luck!