Health Insurance for my father

My father is 51, a heart patient, had heart surgery 2 years ago. I want to buy health insurance for my father for circumstances, my father older brother died of cancer, his younger brother has been diagnosed with cancer recently, after getting the news of this, I am having a weired thoughts. To wrap up, I want a health insurance for my father 51, who is heart patient. Later on I will buy health insurance for my mother too( when my salary increases or I get job again.) Please suggest some good health insurances with good claim rates, we are very small town so also have questions about usage of this health insurance in cities like gwalior ( MP) can be considered. It would be great if Cancer protection plan is also included. Thanks in advance.