Someone had mentioned that online lotteries have been legalized in a state in India. That's great news for OnlineLottery.in. Still, .in is young and I doubt you get much traffic on it, so it may still be a tough sell. It may be better at this point to hold onto it and let the online lottery market grow in India so that you realize some of the potential of the name. OnlineLottery.co.in would actually be better at this point as it likely has more traffic. For both, I think you may be looking at low to mid $xxx, possibly more in the future if that market gets really big. Lotteries are one of the only forms of gambling allowed throughout India, so it's likely a matter of when and not if online lotteries will grow to be a big gambling market.
Dating.ac is okay... .ac is a lower-end ccTLD and I think better would be date or single(s). You still may get mid $xx for it, but any more would be a lucky sale IMO.
.am seems to be good for radio names and little else, so Diamonds.am I think would be about the .am reg fees (mid $xx). The .com may have sold for millions, but that's a rich market that IMO would settle only for .com or maybe the gTLDs otherwise. I don't expect there to be any big ccTLD sales of Diamond(s) stemming from it. Good luck though!