Employment Agreement on a white paper - need to terminate the contract without arising any legal problems

I am Srinivas. I recently joined in a BPO company and during my joining I signed an agreement on a printed white paper ( not a legal bond paper). After a month I couldn't continue in the company due to some issues. Now the HR team is texting me that they will take legal action against me and I have to pay 1 Lakh rupees. Also they added that they are going to block my aadhar and pan card without getting employment in any other companies in future.
Also it is mentioned in the contract that the trainee can terminate the contract without compensation if he is unable to continue the training on medical grounds or if he secures gainful employment.
Now, is my agreement a valid one? What do I need to terminate the contract without arising any legal problems and without any compensation?

Quote: "they are going to block my aadhar and pan card without getting employment in any other companies in future"Un quote: is impossible proposition / can not be done.

Sir,
Then what about the contract?
Is it a valid one?

Agreement in printed paper with sufficient witness is a valid document. Only think they may have to pay some stamp duty when goes for litigation.

There is no illegality in having agreement on plain paper duly signed and witnessed
If dispute arises stamp duty can be paid at the time of admitting the document in court as evidence.
Even oral agreements are valid.

Mr Srinivas ji, How can one block your aadhar or PAN card?
I think they are threatening You?
Pls Keep Cool nothing can happen unless/
provided You have not done anything wrong against the Company & You have sufficient grounds to prove why you left the job? if at all the issue burns further.
I think they wont be able to stretch any more.
It is just my opinion.

The agreement signed by you is valid.
What are the terms & conditions for which they are asking you 1 lac rupees?
Your BPO company is not capable to block the PAN & Adhar in any way.
What reason you offered in your resignation letter?
You reason out any of the clause defy the agreement clause not attracting any financial burden.

They are charging 1 lakh rupee as training fee and one month stipend.
I have mentioned health issue as a reason for my absence.
But I haven't given any resignation letter as they didn't ask any of such thing.