Can My Company Change the Notice Period Without Telling Me? What About My Gratuity?

I was working in this company (Service-based Software) until yesterday, and I have also served a notice period of 15 days. My joining date was August 2014, and I have almost completed 4 years and 11 months. I gave my notice period of 15 days on the 2nd of July. However, the HR and Director informed me that the company has changed the policy, and employees now have to serve a minimum of 2 months' notice period. The Director specifically mentioned that the company reserves the right to change policies at any time (How can they change policies without any notification).

The company did not notify me of the policy change before my resignation via email or provide any written material regarding the new 2 months' notice period. I checked my offer letter, and there was no mention of the notice period. They have withheld my June 2019 salary, which should have been credited on July 10, 2019. Can I still receive Gratuity from the company, considering I am one month short of completing my 5-year term, and I completed my notice period one month early?

What steps should I take?

Please advise.

Yes, the employer can revise the policies from time to time as it might be mentioned in your appointment. However, it should be informed to all employees prior to its implementation. Since you have completed 4.11 years, I would suggest you complete the remaining notice period and get properly relieved. You are very much eligible for gratuity provided you complete 5 years of continuous service. At the time of relieving, make a written request to your employer for gratuity, and your employer is obligated to clear it within 30 days from your date of relieving. If not, you can take up the matter with the Assistant Commissioner of Labour in your jurisdiction. Holding salary after resignation is also not right as per the law. You may request them to release the salary for your day-to-day expenses.

Please let me know if you need any further assistance.