I guess you mean donation through matching donation sometimes run on American express platform?
That is best value for buck of corporate employees to donate to their chosen charity as some companies matching donations as well.
For ₹1 donated, Amex donate ₹1, company donate ₹1 and for 30% tax bracket you save tax of ₹0.3
For every ₹1 donation your favourite charity gets ₹4.2857 & considering it good charity with expenses ratio (~7%) ₹4 will entirely spent on actual cause of charity.