PANEER: Paneer, also called cottage cheese is made of milk protein. Sometimes it also has processed cream to soften its texture which in turn gives your body the not so required fats. If you want to have a normal meal (calories) and want to retain some taste in it, you can choose paneer over tofu in that case.
TOFU: Tofu is made of soybean milk by curdling it into low-fat block. Tofu is easily available in supermarkets in the vegan section. If you are on a weight loss plan and want to reduce your calorie intake, then tofu can be your choice. With less number of calories, tofu has a significant amount of calcium and protein. It is also beneficial for people who are lactose intolerant as it helps to fulfil their calcium requirement. You can alter your diet by replacing paneer with tofu and feel the difference in few weeks.