Letter Received For Breach Of Non Solicitation Clause.

Legally, your PF and Gratuity cannot be withheld or appropriated or denied if you are otherwise eligible. So file necessary claim papers in the prescribed Forms with due acknowledgement. If delayed, take it up legally. However they may pose some problems in settling your salary (raising notice period issue) which also can be claimed in writing, if not forthcoming you have to take it up legally. Pursue this step by step.
kumar.s.

You can forget you about getting your f&f
They are not going to give it to you.
You can file a complain if you wish to the labour officer, but it's a waste of time.
Speak to your hr department and get their opinion.
Ensure they are clear that you will not be able to give them a relieving letter or experiance letter
Hope your current company is better

Hello Amit,
I might be replying this late and hope you have settled the case with your previous organisation. Having read through the clause your previous organisation sent to you, i doubt they understand it themselves.
The interpretation of the clause (quoted below) is that during your employment with the company and after, you cannot ask the employees of that company to leave company or apply to a third party's organisation. Also, you are not to pursue businesses that are similar to the one that your former company is doing until after a period of one year
So my guess is that your current employment is similar to what you used to do at your former company and you are likely interacting with the same customers you used to interact with at the old company and that is why they have sent you that letter.