I have Book of ASP.net 4.0 2010 by kogent learning solution ........... this Book is very large to study ... i just want to know to learn important section of book.. because i have 1 to 2 month to apply for job .... this book is very big i think it will take 1 year year or 6 month to study thoroughly still wont be able to finish it ........ i Know basics of asp.net and C# and want to learn more than basics and can make intermediet level projects

Welll, with knowing the book its hard to give advice. But, in general, are you applying for a particular job? If so, then you maybe able to get a general idea of the tasks involved e.g. is it a job using MVC or a particular database? Otherwise, its a hit and miss scenario, you could pick any one of a range of valuable topics only to find you should have studied something else.
But, pick something you know little about and improve it

what topics interviewer ask most in c# asp.net and sql

Its too big a pool to answer that with any certainty at all. They could ask anything. One strategy is to pick something you know well, or intend to learn well before the interview, and redirect the conversation. They ask about topic A, find some way to talk about topic B.
Confidence is important and being able to show you know something is better than nothing, as is showing you have the ability to learn and adapt quickly.

Do You Guys Know any site where i can prepare for C # asp.net and sql server Interview Step By Step ..

Typing 'C# interview questions' into google gives a lot of good responses.