It is akin to a bond without terming it as a bond.
Are you being given any special training by MNC?
Restriction on number of employees resigning is not in order?
Yes company can try to restrict exits by appropriate policies but cannot lay down quantitative numbers.
The laws of the land for firms under Shops and Establishment Acts of states is generally one month.
The terms of this MNC are stringent and not exactly in consanance with laws as laid down.
Legal battles may ensue if some one wishes to exit and MNC is at advantage because employee fights with own money and has limitations as he may to join some other firm at short notice.
There is no real solution other than legal battles.
25th August 2018 From India, Pune