Is employment bond legal in india

The bond is enforceable if the employer has imparted special training incurring substantial expendiure. It cannot be enforced unilaterally. Stamp duty varies from State to State. 

You are liable to honour terms and conditions of bond submitted / committed to your employer at the time of your appointment / assignment.

The very act of selecting and deputing an employee to another country, giving him preference is itself a great favour and expensive exercise and the employer may incur a huge loss due to sudden resignation and there may be a lot of delay in finding a substitute in the present circumstances.  The bond is enforceable.   However you can explain the so-called personal problems to your employer, and if those problems are really genuine, they may consider relieving you on humanitarian grounds.  But the employer's experience is that those who were assigned such tasks have taken up independent contracts with such relations developed during past employment, and stolen such contracts and resigned from the parent company and facing such litigation in India.