Hi,

The Rbi grade b officer duty is that

Handing the currency issues and its circulation ,

ensuring the nation's  financial stability

handling government  and central bank account

To become ana rbi grade b officer there will be aexam conducted which is a country wide examination in three phases

Preliminary

Mains

Interview

Who gives the best output they will get selected

But first of all you have to know about the exam syllabus

For that check the given link below

https://competition.careers360.com/articles/rbi-officer-grade-b-syllabus-exam-pattern

All the best!