Yea They can be the most sought after but keep in mind, 'sex.in' would be sought after as an adult domain, which as far as indian context goes is still a bit of taboo although they might get a higher price because of the name( as sex.com is one of the costliest domains) and for that case porn.in, but same thing applies here too. And there is not much specialty in fun.in.
I second what Maverick said, lll.in should be one of the most popular one.