Hello Fatima,

Unfortunately the answer for your question is Yes, because class 11 is considered only the qualifying class which gives you the entrance in the 12th class that's why the whole preference is based on class 12th marks.

The admission in DU is mostly merit based but even though you do not have good marks in class 12th ie you have 60% in class 12th then it's enough for you to get admission through entrance test. 

For more information you can either ask me or you can visit the official website www.du.ac.in

Hope I was able to clear your query and hope you do well in future.