The initial screening was done based on a computer based test:
the sections included: quantitative, verbal and analytical thinking
quantitative had comparison, probability & stats, series, areas n volumes, geometry n trigonometry questions
with a number of reasoning ones
verbal section had reading comprehensions, antonyms, synonyms, sentence completions etc
Analytical section had math puzzles - which were quite tough
1. Asked in detail about undergrad projects
2. Asked me to explain about my technical papers
3. Why I did not score well in a particular subject
4. Favorite courses and least liked ones
5. Asked about co curricular activities
6. why I wanted to join TCS