It all depend on case to case. If your case is strong then your will get claim but regular followup is necessary. Check following IRDA Link for read up.
If Your Claim is Denied
Start by reviewing your paperwork file. Then call your Insurer's customer service. Clear your doubts on claim and ask why the claim is rejected. Be sure to take notes on all phone conversations, including the date and time of the call, the names of the people you talk to and what was discussed.
File an Appeal with Insurer
If speaking with a customer service representative does not work, you may have to escalate to a formal written appeal. You need to provide all the information in writing with supporting documents including copies of bills, hospital address (where treatment is taken), TPA deatils if any and your physician's statement about why your treatment was or will be necessary.
Submit following Documents with your Appeal
1- Your health insurance policy
2- Copies of denial letters from insurer
3- Copies of any correspondence between you and your Insurer, or between your hospital (such as your doctor or lab or TPA)
4- Copies of claim form
If nothing happens follow >take's procedure -
Approach Insurer First in writing > (No Result) Approach IRDA > (No Result) Approach Ombudsmen/Consumer Forum