Any agreement signed under duress is voidable. You can challenge the validity of such bond on the above ground. 

They will definitely be in a position to sue you in the court of law. However, to enforce a service agreement, it is necessary that the bank must have incurred certain expenses in imparting you training and education. So, if you are trained and awarded Diploma at the expenses of the bank., bank can definitely sue you.

See they are also having signed cheque and agreement they can file suit.for the recovery of the amount.

They shall file suit and you have only option to contest same before the court.

You had signed the bond 

2) if you have breached terms of contract bank would sue you to recover bond money 

3) your employer has spent money on your training 

4) you would be declared an absconder and it would affect your employment prospects 

You reply to the notice through a lawyer. You can contest the case if any filed with the bank. You don't have any other remedy

You have to clear the bond amount signed by you in agreement.

Otherwise they can initiate recovery suit against you.

The lien will be deducted from the amount they are demanding from you. 

1. Since you absconded and violated the service contract bank has the right to recover liquidated damages from you by filing a suit for recovery of money on account of breach of contract.

2. If there was a clause in the service contract which authorised the bank to mark lien on your account then bank can do it, else the marking of lien can be challenged through a suit for declaration in the civil court

You should at least opt for the professional ethics which you do not , professional ethic means at least has to resign on some grounds then it was easy to fight with them but now as you are absconder then there is no way in spite to buy back the bond period so negotiate with them for the same and try to pay by EMI.

Vanished.

1) since you left organisation before expiry of bond period bank is seeking to recover money for failure to serve bond period 

you can take defence that coma y did not spend money on your training 

But still you have signed the Bond contract for particular period and you have not completed the bond period. 

The bond agreement may be declared void if you challenge its legality on the ground that it was signed by you under duress. 

See you have ground since paying the EMI so there is no legal debt you have can reply notice and contest same before court.

You can contest the case on merits

It is legal in India to work with bonds that prescribe a reasonable penalty as compensation in case of breach. Bonds that are prima facie unconscionable are illegal. An employer expends resources to train his employee and hone his skills. ... To this end, bonds stipulate a period of continuous employment.

The employee, if he so wishes, is at liberty to discontinue his employment during the specific period. However, he is required to to pay compensation to the employer on doing so.

A bond that prescribes an unjust amount of penalty or a work tenure that is unmistakably long or prohibitions that are unreasonable is void for being an agreement in restraint of trade. 

However, bonds that prescribe reasonable compensations for breach are valid.

You may challenge the same in court of law on merits and documentary evidences in your support

Section 27 of The Indian Contract Act, 1872 invalidates agreements that are in restraint of professions, trade or business. For a valid contract, the restraint must be reasonable and lawful, and not unjust and arbitrary.

Employment bond is generally a contract between the employer and employees, and hence subject to the provision of The Indian Contract Act, 1872. It is anemployment bond with a negative covenant. ... Also, the agreement must be reasonable and legally enforceable.