Taxation of cash deposits

Reimbursement .... not taxable.

So should I report it as exempt income (or something else) in ITR?

1. The above transaction is not an income as explained by our respected expert. This is nothing but a reimbursement made by your friend for which you have paid on behalf of him. Income tax will be payable only for your income and not for reimbursement. No need to show anything in ITR. 
2. However, the practice may be subject to question by the department if the amount if high. As per sec 68, unexplained cash credits will be subject to tax at a maximum marginal rate. In your case since you will have an explanation from your side to make if the department raises a question, there should not be any problem. And the above amounts were transferred to your credit card account which will back you up for your explanation. 
3. It is always better when it comes to income tax matters to get the amount from the payer through DD or cheque. (non-cash mode) 
Please correct me if the above solution has an alternative view.