Pros
The best reason to work for TCS is that its an established IT company in India. Its been in business for the last 41 years. Job security is granted. Its an IT goverment. There are good policies when it comes to employee social welfare. I hope there will be no IT company in India where you will get pension , family pension after retirement. It gives medical reimbursement for upto 5 lakh per annum at a very small premium of around 4000/- per year. Good company to join when you reach the retirement age.
Cons
Career growth takes a negative trend while you start working for TCS. If you are a lateral TCS deducts half of your experiance. You will feel the pinch of it later. TCS recruits 3-4 years experinaced professionals and make them work hard for atleast 4 years before they give promotion and increment. There is too much of office politics happening in TCS. Hence it has become a government office. Your career growth depends on your ability to keep your boss happy. Deserved never get promotion. Employee rating and performance pay is fake.