Can A Company Reclaim Sales Incentive After The Employee Has Resigned?

I was working in a mutual fund distribution company. One of the investors withdrew the fund before the clawback deadline and the company had to payback the distribution income. I had received the incentive from the company when the fund was invested. Now even though I have resigned, the company is asking to pay back the incentive. What should I do? I was under notice period when this happened. I am yet to get my final settlements.

Obviously company is not going to pay you incentive in case where the investment has not materialised.
If you do not pay back voluntarily,they will adjust with F N F.
Check up with your friends how such cases have been tackled earlier.
I am sure it is not the first case where fund has been withdrawn or cheque for investment has bounced.

Is it legally binding on me? Can they file criminal/civil case against me if I refuse to pay back?

If you are not entitled for the incentive,why try to retain it?
It is not worth entering into a legal battle over the issue.

It was option of the investor to dis-invest in the fund which he has exercised.the commission was not due to you until the option period was over. Correct me if I am wrong. So, do not be greedy. If it is not due to you, better option is to return it to those to whom it belongs.
The Company can sue you, remember it is much more powerful than an individual is. It has large pool of resources and can engage you in an endless court battle, which I assume you can hardly handle/afford. Instead use the time to move on with your life.