What Technology is needed by many companies in .Net, especially in C#

This is an insane question. No-one needs LINQ, for example. People need ASP.NET only if they are creating a website. They need Silverlight if they want to use C# to write a website that is as powerful as flash. They need WPF if they want a cool UI. They need winforms if they want a standard looking user interface. They need ADO.NET if they are using a database. What they NEED, depends on their requirements. What they use depends on preferences and what they think is fashionable. The number of people converting perfectly good code to use LINQ, for example, is far more than makes any sort of sense.

As to what Indian teams seem to be falling over themselves to apply, if they need it or not, I'd say that knowing the names of a couple of design patterns, and the ability to ask LINQ questions here because you don't understand LINQ at all, but can copy and paste the answers, should get you a job at any Indian outsourcing team you might be applying with.