Only an Institute will not help you to be the Master of any technology... Now a days Institutes will only give you the basis the rest has to be done by you...before you join any institutes be sure you see who is going to teach you...and ask him to tell you something about ASP.NET or .NET and see what he replies...how professional his answers are..and then decide...
Hey, I will suggest you to go for online study and just practice daily whatever you learn or the coding you do just do that repeatedly on different problems.This will build up your confidence and you will learn new thing daily.You can follow W3Schools tutorials " http://www.w3schools.com/aspnet/ " or you can even check a link " http://keenesystems.com/Services/SoftwareDevelopment.aspx " for any help from developers if you need some. Wish you Good Luck.