Dear Student,
Glad to inform you that having 66% in your 12th you're definitely eligible for getting admission in B.com as you clearly surpass the minimum eligibility criteria of having minimum of 50% in your 12th. But if you aim at the University of Delhi I'm sorry to say but I find it almost impossible for you to get admissions in B.com in DU with 66% in 12th. I might suggest you to go for a reputed Private college instead like Amity, Sharda, Galgotias,etc. You are definitely not clear with your question as you haven't specifically mentioned the college you are asking for.
Hope this might help you.