Termination rules West Bengal - No prior notice, no reason for termination was given

I am working as a Branch Manager in a leading NBFC and posted in West Bengal. Another branch manager of some other branch, has been terminated only stating a line "Your service no longer required". The manager was having a more than 5 years service. No prior notice, no reason for termination was given. The gentleman is perplexed in this order. He has not been paid a single penny on the day of termination and at the same time the salary will also held for minimum 6 months, in the name of final settlement. Tomorrow this could happen with me also. Kindly give the necessary guidance to retaliate this including any specific rule by Govt of West Bengal to protect the interest of employee. Thanks.

Dear Sabyasachi,
Your fears could be correct or misplaced also. We the members of this forum are outsiders and cannot understand the internal dynamics of your company.
Financial misappropriation could be the reason for the sudden removal of your counterpart at other branch. Otherwise employers do not remove someone with five years of service unceremoniously. Nevertheless, your employer should have conducted proper enquiry and then terminated him, if found guilty.
How many similar terminations have happened in the past? Is on-spot termination order of the day or is it isolated incident? If former, then be proactive and start looking for job. If latter then relax but make sure that your hands remain clean.
Thanks,
Dinesh Divekar