80G and other

hi sir I am Madhu

sir my doubt is a company donating 1000000 and more to aTrust. and asking 80G ,12AA,FCRA.35AC 123 letter and documents
what is that letters ???
I asked him why u donating that much amount ?
he said for deductions purpose

Total will be comes under 80G?

my doubt is instead of donating 1000000 he can pay only 30% tax on taxable income & he can save it right ? then y he is paying sir ?
I think that's not deductions purpose !!

please tell me if anybody know about this

thanks in advance