Dear Aspirant,

Please mention of what stream you are talking about in the comment below. However, in a general case even if you think that you have wasted your XI there is a chance to make up for it in the XII and also take a drop year after that if required.

You can prepare for almost all the competitive exams in a period of 1 year if you prepare with dedication and time table.

Hope this helps. Thakn you.