How break employment bond without paying certain amount?

You are legally bound to honour the contract you have signed with your employer. Take legal advice before doing anything foolhardy which may put you to unnecessary legal expenditure.

Facts posted suggest the terms of the employment bond to be void on account of the provisions  of Section 27 of the Indian Contract Act:

Section 27.   Agreement in restraint of trade, void.

Every agreement by which any one is restrained from exercising a lawful profession, trade or business of any kind, is to that extent void.

Exception 1.Saving of agreement not to carry on business of which good-will is sold.One who sells the good-will of a business may agree with the buyer to refrain from carrying on a similar business, within specified local limits, so long as the buyer, or any person deriving title to the good-will from him, carries on a like business therein, provided that such limits appear to the Court reasonable, regard being had to the nature of the business.

It is the settled legal position that terms of the employment bond are enforceable only if the Employer has incurred  substantial expenditure in imparting special training to the employee.

In the absence of any enforceable debt, the blank signed cheque cannot be made use initiating action under Section 138 of the Negotiable Instruments Act.

Both of you are bound by terms and conditions of appointment.