You can do Psychology(Hons.) from DU if you are having these subjects.
Eligibility says for domain, you have to select 2 subjects from B1 (in your case it can be Chemistry/Maths/Physics) and 1 domain subject either from B1 or B2 list, which again contains your existing subjects.
So, don't worry. Go ahead and select your subjects for Psychology (Hons.) from DU.
Apart from Section 1 i.e Language Test, you will have to give 3 domain subject tests.
Best Regards !!