You know that if you give a notice of your quitting the job within 6 months (i.e. during your probation period), you have to give 1 month notice period. Thereafter you have to give 3 months notice period.
In spite of knowing the above position, you gave the paper to quit the job, ON THE DAY when you completed 6 months of service.
Since you gave the quit letter on the day of completing the 6 month service, naturally you have to serve 3 months notice period.
YOU COULD HAVE GIVEN THE QUIT LETTER 2-3 DAYS BEFORE COMPLETING 6 MONTHS SERVICE. WHY YOU DID NOT DO IT? WHAT YOU WERE WAITING FOR? YOU CREATED PROBLEM FOR YOUR SELF.
I DONT THINK YOU WILL GAIN/ACHIEVE ANYTHING BY APPROACHING THE LABOUR COURT. EVEN THE LABOUR COURT PROCEDURE WILL EASILY TAKE 2-3 MONTHS TO CONCLUDE.
THEREFORE, IT WILL BE BETTER FOR YOU TO SERVE THE NOTICE PERIOD WITHOUT PROBLEM, AND GET A RELIEVING LETTER WITH F&F SETTLEMENT.
AT LEAST IN FUTURE USE YOUR BRAIN. TAKE THINGS SERIOUSLY. DO NOT DELAY THINGS UNNECESSARILY.