Hii,

I am sorry to hear about your certificates.

Yes, you can still apply for a B.Sc. Psychology study with a 12th grade certificate. Many institutions accept the 12th grade mark sheet as proof of eligibility. To complete your documentation, you may need to obtain a replica of your tenth and eleventh grade certificates from your school or board.

Contact your school or board for assistance with this, and mention your status when applying to university.