Can I substitute cottage cheese or Indian paneer for ricotta?

I use cottage cheese for ricotta often. It is a bit saltier tasting to me, but you can duplicate the texture by running it in your food processor

Indian Paneer by itself is way to hard to match the smooth creamy consistency of ricotta. and the cottage cheese tends to be soft & lumpy. You may want to try combing the two (3 parts cottage cheese to 1 paneer (crumbled)) and pulsing the mix in a food processor to mimic ricotta. Better yet.. Make the ricotta from scratch. here's the link to a foolproof recipe
http://food52.com/recipes/11403_creamy_homemade_ricotta
hope this helps