Health Insurance for a 65 year old

Hello, my father is 65 year old and he has no health Insurance till this time but I like to take one for him and he only has some common health issues that commonly occur during this age ( taking medicine for diabetes, cholesterol and BP). Once when I asked the new India assurance about my need to take a health insurance for my father they said that it would cost nearly 25000-30000 to pe paid annualy with the given scenerios. Give me a better suggestion about the the health insurance that I can take for my father with lower payment but with no cooling period. Any other unique informations regarding the health insurance is also much appreciated.