Need to choose from all the health insurance providers for my Parents

Few details - City Of Residence - Bhubaneswar , Odisha , India 1. I need Floater Insurance Policy for 5 lakhs for Mom and Dad 2. Better if it covers Yearly Free Annual Medical Check up 3. Does this plan cover pre exiting diseases (Diabetics and high BP) from day one. If not then after how many years. Example - *Covers pre-existing diseases from the second year onwards. 4. Does the company offers a no-claim bonus or discount if we didnt use this in previous year 5. Does this insurance give me an option of increasing my sum insured in future ? 6. Will I be able to use portability in future with this product ?  If some new better health plan comes up can we switch ? 7. I can afford yearly premium of around 25k 8. Is there any age limit ..till which age I can renew this insurance Example till 75 years or more. 9. Does this insurance gives Guaranteed lifetime renewals with same premium.