An employment bond is an agreement between an employee and employer. The agreement contains certain terms and conditions as well as rights and obligations. For instance, you have a right to be paid for the work you do, whereas the employer has a right to give rational instructions to you, for you to be able to work at your job properly.
It is Company own HR policy to retain the employee in the company.
Yes, it is applicable in India. As per Indian Contract Act, 1872.