Hello Gaurav

According to the SBI PO eligibility criteria, Candidates should hold a graduate degree or equivalent examination from a recognized University or by the Central Government to be eligible to appear for this exam.
You cannot appear after class 10th, you should complete your graduation first to be eligible.

You can go through the link below and check the detailed eligibility criteria- 

 https://competition.careers360.com/articles/sbi-po-eligibility-criteria

Good Luck!