Yes in some policies there are sub limits as given below.

ICICI Lombard

1. For policies with sum insured over US$ 100,000, the limit of liability of the company will be restricted to US$ 100,000 per sickness, disease or accident.

2. For persons aged 56 years and above, the maximum eligible medical expenses per sickness, disease or accident that may lead to one or more medical expenses and/or hospitalization expenses are as follows, irrespective of the plan / option purchased. These limits are further restricted to the maximum sum insured specified in part 1 of the schedule.

1. Hospital Room and board, and hospital misc. expenses -maximum US$ 1,600 per day up to 30 days 
2. Intensive care unit - maximum US$ 3,000 per day up to 7 day
3. Surgical treatment - maximum up to US$ 12,000
4. Anesthetist services - up to 25% of surgical treatment
5. Physician's visit - maximum US$ 75 per day up to 10 visits
6. Diagnostic and pre-admission testing - maximum US$ 750
7. Ambulance services - maximum US$ 500

Tata AIG

For persons aged 56 years and above, the maximum eligible medical expenses per sickness, disease or accident that may lead to one or more medical expenses and/or hospitalization expenses are as follows, irrespective of the plan / option purchased. These limits are further restricted to the maximum sum insured specified in part 1 of the schedule.

1. Hospital Room and board, and hospital misc. expenses -maximum US$ 1,500 per day up to 30 days 
2. Intensive care unit - maximum US$ 3,000 per day up to 7 days
3. Surgical treatment - maximum up to US$ 10,000
4. Anesthetist services - up to 25% of surgical treatment
5. Physician's visit - maximum US$ 75 per day up to 10 visits
6. Diagnostic and pre-admission testing - maximum US$ 500
7. Ambulance services - maximum US$ 400

Future Generali

For persons aged 56 years and above, the maximum eligible medical expenses per sickness, disease or accident that may lead to one or more medical expenses and/or hospitalization expenses are as follows, irrespective of the plan / option purchased. These limits are further restricted to the maximum sum insured specified in part 1 of the schedule

1.  Hospital Room and board, and hospital misc. expenses -maximum US$ 1,750 per day up to 30 days 
2. Intensive care unit - maximum US$ 2,500 per day up to 7 days
3. Surgical treatment - maximum up to US$ 12,500
4. Anesthetist services - up to 25% of surgical treatment
5. Physician's visit - maximum US$ 75 per day up to 10 visits
6. Diagnostic and pre-admission testing - maximum US$ 1000
7. Ambulance services - maximum US$ 500