CRO = Customer Relation officer.. the grade level is different in different banks. as a CRO You are required to sell the bank`s products and make efforts to increase the clientèle of your branch. You have to achieve targets i.e bring deposits. Further you have to maintain banking relationship with customers and facilitate/ guide them (in some banks you are required to welcome/greet the customers) CRO is a low level job and not technical.

In interview, you will be asked questions like

How will you sell the banking products or bring deposits?
or How you greet customers?
what do you know about CRO designation or history of a bank you are applying?
may be they will assign you some situation and ask you to solve the problem.

CRO is a low level job, can be hectic for those who lacks in presentation skills, but a CRO can be promoted to Branch manager or Relationship Manager (depends on how much deposit you bring to the bank or successful in achieving your targets which is mainly to bring deposits)