Is It Fair for My Company to Demand a Joining Bonus Refund After Resignation?

My company paid me a joining bonus that was distributed in equal installments over 12 months after I joined. There was no condition in my offer letter stating that I would need to repay the bonus if I left within 12 months. However, I have now resigned after 8 months, and the company is requesting that I return the 8 installments of the joining bonus, including tax.

Is this legally correct? Can I dispute this decision?

Policy Stipulations for Joining Bonus

Does your company website or HR department have any policy stipulations regarding the terms and conditions of the joining bonus? Also, check your offer letter—does it mention that the management has stated that rules, procedures, etc., are subject to change at the discretion of management? Normally, the bonus is recovered if an employee leaves within 12 months of joining. However, you can challenge it if you have the time and energy since there are some loopholes, such as no mention of repayment, etc., in your case. This will also have tax implications.