Pros
Job Security - Firing is the last thing you will face. Even the least competent person can find a post on which they can survive. Basically a Private Government job type. Less pressure of work. Sometimes Flexibility.
Cons
Least learning - You won't learn much skills to land a job elsewhere as majority are support based jobs for engineers Worst compensation - Salary provided for the post is less than the industry (and worst for freshers). Increment is a joke. No growth of career. You won't get to work in the domain you want 8/10 times. Hence you will be Jack of all trades, master of none which affects you once you cross 6 years of total work experience as prospective employers expect expertise in something which you cannot learn here due to constant random project change forced upon you.