The testing platform was AMCAT. A question once attempted cannot be returned to.
The test contained 3 sections:

1) Computer Science related MCQs (TIme: 20 minutes, Difficulty: Easy for CSE, Medium for other branches)
Questions about data structures, algorithms, finding time and space complexity, sorting, DBMS, oops, etc.

2) Coding (Time: 45 minutes, Difficulty: Very Easy)
This section was very easy. The difficulty level was below First Year CP level. Although the time given was 45 minutes, it took hardly 10 minutes to complete. The questions were as follows:
(q1) Given an array, count number of integers find the number of integers less than a given integer k.
(q2) Printing a pattern of integers

3) Probability and Statistics (Time: 25 minutes, Difficulty: Medium)
The section contained passage based questions on probability and statistics. Various charts, Venn diagrams and information were given and questions were asked on the same. The difficulty level was medium but time was less.

32 students were shortlisted from 64 applicants.

After the PPT shortlisted students were announced. These students were asked to write a 30 minute written test. The test included the following questions:

1) Camel and Banana Puzzle (https://www.geeksforgeeks.org/puzzle-15-camel-and-banana-puzzle/)
2) Grandma and Cake Puzzle (http://www.crazyforcode.com/grandma-cake-logical-puzzle/)
3) Find maximum possible stolen value from houses (https://www.geeksforgeeks.org/find-maximum-possible-stolen-value-houses/)
4) WAP to find ranges in an array (eg. for [1,2,3,5,6,9] return ["1=>3", "5=>6", "9"])
+ some logical questions

All 32 students were allowed to sit for the interviews.

The interview started with questions about my resume, family background etc. If there is a sudden downtrend in your CGPA expect questions about it.
Also, questions like "Why should we hire you?" and "Tell me one strength/weakness."
I was then asked a series of technical questions for example,
1) Complex SQL query (don't remember the actual question)
2) Given an array, find the number of Pythagorean triplets. (first solved in O(n^3), then improved to O(n^2)
3) Given a singly linked list, detect a loop and remove it.
etc.

Many students qualified for the next round.

The interview included the usual HR questions, for example, "Where do you see yourself in 3-5 years", "How will you bring value to our company" etc.
I was also asked questions based on my answers in the written test. I was asked to explain the logic behind my answers.
The interviewer asked me if I had any questions. I asked about how the company decides which department an IT professional should belong to and about the scope of Data Analytics in Wells Fargo.

Finally, 9 students were selected.

Good communication skills is important. Maintain eye contact, smile when appropriate and give a firm handshake.
As for the technical part, basic preparation is enough.