"Heart surgery in India, free of cost for children(0-10Y)"
From the US, an economy Air-Ticket cost to Bangalore, India could range from USD 1500 to 2000 per person depending on the season. .......this is for a round ticket cost ex USA.
From UK/Europe the ticket cost would be maybe 30-40% less.
One must also factor in the additional cost for lodging and boarding expenses in Bangalore during the full tenure of the surgery+rehab...
..but I guess most budgeted amounts would be met, given the plethora of hotels from 5 stars to serviced apartments, to much lesser starred hotels in Bangalore.