Is it safe to use my Indian MacBook Pro charger in America using a simple adapter? I am using a local adapter to use my Indian MacBook charger in the US. I am wondering is it safe to use so.
Absolutely fine, so long as the original to adapter interface makes a good connection.

Alternatively, you could try to find a specific flat pin adapter to run directly from the charger - this is just a simple eBay UK search with similar plugs … http://www.ebay.co.uk/bhp/apple-us-plug