I think, .co.in _________________________________ Register .CoM .Net .Co.Uk Etc Domains for FREE warrioroffers.blogspot.com/2008/02/register-com-domains-for-free-and-make.html
Predominantly, it was co.in but .in seems to be getting a lot of exposure in our country (India) off-late.
Well i think .co.in is 10 times better than .in domain.. It really looks a class apart.. All major sites have their sites co.in yahoo.co.in google.co.in nokia.co.in www.deutschebank.co.in All major govt. sites and big corporates including reliance airtel etc have .co.in
Both have about the same appeal. If a company site, use .co.in - if a games site or whatever, use .in Little to choose really between them both.