Complete 5 years as a permanent employee to get the gratuity amount?

I am a teacher in a private school and I am being told that I'm not eligible for gratuity. The reason being that I joined in July 2012 and after that I was on probation for 2 years and so I haven't completed my 5 years of being a permanent employee. Is it true that I need to complete 5 years as a permanent employee to get the gratuity amount.

Dear Ruchika,
As per gratuity act it states that you need to complete 5 years of service to get eligible for gratuity but nowhere it is mentioned as service after got permanent. You can ask your HR department to provide / show the written communication where it is been stated.