when some one types any of the two url, the website will load from the same server.
What shows in the url? Can you see both example.in and example.com?
Will this affect the website or its performance in the Search Engines.
Quite simply yes, it will lead to a little bit of confusion for a short while but then the search engines will decide which is the more important rather than having a duplicate in the SERPs and it could go either way, they may choose example.in as the older and original!
If you want example.com to be the primary site then either 301 example.in or url forward it from your registrar.