Extra Income potential for Government

There is big loop hole in income tax structure of India. Although all Indian pay tax direct or indirect way . But here i hit only religious institution & trust , who are giving tax exemption to those who donate to their trust . Here approximate 25 % of Indian government income trapped here . Most of the Institution or trust return a huge amount of money of payer just after taking a little amount. Here you can imagine how much loss to govt. is there.
I discuss it here briefly. e.g Tax exemption limit is 160000 Rs & above it upto 500000 Rs , a person have to pay 10%. e.g a person have a income of 170000 Rs then he have to 10 % on 10000 Rs i.e 1000 Rs Tax annually but if he donate 11000 Rs to some temple or religious institution or trust then his income remains 159000 Rs i.e he will be fully exempted from tax. But when he pay 11000 Rs to to trust & they return him 9000 Rs ( as they usually do ) Then clearly there is a loss of 900 Rs to Indian Government.
Is it justicable . So Indian govt. have to see this loop hole so that this type of unseen corruption can be eliminate from our society. Amount which i discuss here is in just rupees but corruption in this game is of 100000 Crore. This amount can boost the Indian economy very fast.
Altough there are so many trust & religious institution which collect & expend donation honestly but main concern is only from dishonest People .