$10million is a large amount of money and your ability to use this for interest to live on is going to depend on the particular bank you're working with. This would be a large enough amount where traditional banking doesn't apply. You would have a private banking money manager handling your account. Interest rates would differ depending on what type of account you would have the funds in. The private banker would be able to direct you and come up with a strategy.
Look at the interest rate of a savings account and that would be the amount generated for a year based on the present balance in the account. Divide that out by 12mos and you'll have your monthly income.
Of course, taxes would also be due on that income as well.
Well...average interest rates in savings and money markets are not great out thee right now. It could be from $.50 - $1.50% per year. Depends on the bank and there could be fees, etc. You would just have to research a bit. you would be better off looking at a CD or investment account. If you had a 1.5% annual percentage rate on $10mil, that would equate to $150,000 per year in interest. That is about $12,500 per month.
Look at this website under Checking & Savings and CD's and Investments. This will provide you detail on banks around the country and what rates they're paying. You can research everything in one place.