Pros
Work on latest technologies and software. Employees and management are very nice and supportive. Management is well trained on how to lead and motivate employee for any work. Indian projects give lot of exposure for learning. Managers are always approachable when we were posted at any Indian Client Side. Both short and long term projects are available. You might also get an international opportunity if lucky. NIIT Tech has an excellent training programs available to choose from (free of cost) - which they give to their developers and on latest technologies.
Cons
You can just learn and gain experiences for various technologies. But NIIT Tech is not a good pay master for Indian Projects. Nothing to offer in terms of money. You will end up doing so much task and handwork but they wont give you any monetary benefit. When you don't have projects you might have to go resource pool which is very scary as they are not well maintained and no sufficient arrangement for people sitting at resource pool. Systems or machine are quite old at some of the places.