Hello!

NO, any computer certification of sbi bank po isn't compulsory. Th eligibility is that you should have a graduate degree from a recognised institution. Although you should have studies computer as a subject im school/college. As working basic knowledge of computer is required as the exam is also online mode. You don't specifically need any certifications for that compulsory but getting certifications may help to build your profile and also help in working as a PO.

I hope this helps.