I think both ccTLDs are well known in india. I like .co.in only for hack domains ex earn.co.in (earn coin) Between .in and .co.in , better is .in of course.
.in is shorter and hence, it is easier to remember. The drawback is that .in domains are costlier when compared to .co.in (I use GoDaddy) If u can get it cheap somehow (from other registrars, etc), then also, the renewal is not as cheap.
.in extension for India .co.in extension for commercial (India) .net.in extension for network (India) .org.in extension for organisation (India)