"idea" / bsnl is great.... if u buy bsnl make sure your phone is compatible with that sim card.
avoid "reliance" this card never works anywheere.
but remember if you pass thorugh some villages , your sim card might not work. goa is not that well connected.
but if you want to make international calls its cheaper to call from a landline public phone.
happy travelling.... i have a few weeks to go... cannot wait !!