We assure you that exchange rate you see at the time of donation is purely notional - funds raised in all foreign currencies (we support around 12+ international currencies apart from INR) are held in our US custodian account and transferred as $ when the organizers request the same.
The exchange rate they receive in Rupees is based on the date of receipt of funds through their bank. For example, the current (27-04-2021) notional FX rate on site is 52 INR / SGD whereas the equivalent FX rate at the time of transfer (on 27-04-2021) to the recipient is around ~ 55 INR / SGD
The notional value of keeping a slightly lower exchange rate for display is to ensure that fundraisers don't suffer from a shortage should there be a fluctuation/volatility in currency movements. So we are conservative with our display. Please note that we make no money directly or indirectly in FX arbitrages or floats associated with it.