Both are legally enforceable.
In both the cases you must read the conditions carefully before you sign on the dotted line.
It is probably for the first time some one has asked the implications before executing the service agreement/bond.
The salary in the offing is not that big that you may blindly fall for it. In the offer letter/appointment letter is there any clause committing annual rise/increment? What is the notice period and notice pay? What are the office hours? Are you entitled for over time?
What is the penalty if you break the service agreement/bond? Is the employer asking for any surety and any advance or FD to be pledged by you?
The sum total of penalties to be paid by you e.g. notice pay, penalty for breaking bond must be seen.
If you decide to separate say after 1 year and you end up paying 3 months notice pay say Rs.30000, and say Rs 100000/ for breaking the bond, shall imply that you have to shell out Rs. 130000/ hence you shall be working for the employer and paying salary to the employer instead of getting salary from the employer.
Companies throng bigger/famous, lesser known institutions as the employer gets qualified trainees who ignorant of their rights and would jump for the first offer without analyzing the implications.
You may compare other offers and weigh your options.