Whether it is one year or 4 years, they will not sanction your claim.
They will reject your claim as mentioning it is pre-existing diseases.
At the time of insuring, if you pay a premium for 3 years at one shot, -If you claim after discharge from hospitalization, at the end of the day, They will cancel your policy stating as per nondisclosure of diseases, your policy canceled that too within one year.
They will not refund the remaining premium also.
Please do not go with this company they are money minded and totally react differently at the time of claim. Instead of going to this company put that premium money in dustbin are same.