At many Indian temples, on entering the inner sanctum, devotees and foreign tourists alike are often met by a priest who will apply a tilaka (dab of paste) to your forehead and perhaps "gift" you a jasmine flower... and hang around expectantly holding a donation tray.
What is a suitable amount to donate? This is assuming you're visiting a temple that does not have entry fees/tickets for tourists -- although I'd be keen to hear whether or not this exempts you from paying the priest.
You do not have to donate anything in a hindu temple but you as a foreigner some priests may expect money from you. They even ask you to donate 500 rupees (about 7$) or even more. As mentioned above you don`t have to donate anything.
In some temples you will not get any mark on the forehead (it is called "Tilaka or Tilak") or anything like that unless you present a gift to the God/gods/priest. Mostly you buy a coconut or flowers from the shop outside/inside the temple.
In some tourist places they even ask you to do some havan/puja (hindu rituals) and ask you for the money and that can be even hundard of dollars. So be aware of such kind cheats and tourist traps.
So if you want to visit a hindu temple you can give whatever you want from 10 to 50 rupees (20 cents or about 1 $) or more as you like.
Whereas if you go to a sikh temple you can also donate whatever you like but don`t miss the langar (free food) which is very good.
As much and as little as you want.
In comparison, In Europe, when visiting a nice church, I will sometimes leave a few coins or something like that, maybe up to 1 dollar, but usually a quarter. (or Euro equivalent)
