My f2 is rejected second time I was unable to no why there are rejected

Actually I went to USA in December 2015 for study’s, but the home land securities stopped me because of the college ( I got visa for silicon valley university) I had doubt that because of this they are rejecting my f2 visa or any other reason I am just unable to now. So can you please suggest me what to do?

F2 visa stampings can be very tricky as it can be hard on the F1 student, if they do not have funding, etc. It is usually up to the discretion of the visa officer to make that decision based on school, funds availability, etc. All you can do is make sure your primary F1 sponsor has the funds to support you financially and try again. It is hard to say.