Hi
1) You can ask your banker's to open an extension counter in your hospital or you can have a tie up with an authorised forex dealer who can set up a help desk at your hospital and help overseas patients exchange their foreign currency.
2) In today's scenario, banker's / forex dealers will be more than willing to set up counter's at your hospital itself free of cost, if the patient volumes are decent enough for them to sustain their costs.
3) Now coming to question of accepting cash for any transaction above Rs2Lakhs, the hospital has to accept card payments or online transfers only for payments in excess of Rs2Lakhs, as the hospital becomes liable under Section 269ST of Income Tax Act if it accepts payments in cash in excess of Rs2,00,000-/-
4) Some hospitals are using methods such as making
a) Separate cash billing in case of medicines and consumables in name of a pharmacy,
b) Separate cash billing in case of diagnostics(xray, MRI, etc)
You should speak to your chartered accountant to understand the taxation , advance transfer pricing related issues etc if choose to have separate entities for pharmacies and diagnostics.
Hope this information is useful.