You have approached this forum for the format of the agreement between employer and employee for the lock-in period of the employment. However, have you studied the efficacy of these agreements? Such agreements may create deterrence but do these bonds really have positive impact on the business? To contain employee attrition, it is important to make service conditions attractive. What steps have you taken to do that?
Let me give you another viewpoint as of now.
If employee attrition has increased then the first thing that has to be done is to do "Employee Attrition Analysis". Have you done that?
Secondly, you could have checked this forum before raising this query. Look at the right side bar and you will find the posts about attrition analysis. Earlier, I had given exhaustive reply about attrition analysis. Check the following link to refer it:
Earlier there was a report on Times of India on why employees quit their companies. Click the following link to refer it:
Bosses, not money, make staff stick to company - Times of India
Go through the above links, do the attrition analysis and come back to this forum with your action plan to contain the attrition. Last but not the least, what about your management, are they worried about employee attrition? Will you get support from them to retain employees?