Online round included 2 tests.
1st one was very easy. It had 48 questions for 6 mins so the time constraint was very limited and you need to answer maximum questions in that small time.
The question are simple addition, square, greater than lower than format but it's roughly 7 sec per question so do mental maths and avoid the questions which are purposely put to waste time.
Test 2 was just after test 1 which had somewhere around 20-30 questions which were basic aptitude questions for 1 hr. General aptitude preparation is enough for these questions.

It was a game related to stock market.
7 groups of 7-8 members each were created for further screening.
No prior preparation is required for this round. Just listen carefully to the instructions provided and clear your doubts there if any. (I won't explain the game during my experience as mostly the game will be changed or

Learn tricks for quick maths. They are useful interview round.