Promotion to IT Analyst

What are the requirements to get promoted to IT Analyst in TCS?

By 'A' band in 3 consecutive years, will I be able to get promoted to IT Analyst? After how many years you're eligible for IT Analyst? Or it depends entirely on politics? I'm not so involved in Politics.

I currently have 3.5 years total experience in TCS(first company). In last 2 years, I have got 'A' band, and in one of them had got top performer hike of around 14.3%.

This year also, there is high chance that I'll get A band as recently Customer has sent an appreciation mail regarding me. Also during meeting my speed manager said that we have received very inspiring feedback regarding you from customer.