Who are the best professors from Mathematics department at IIT Kanpur?

My sister was a student in the Mathematics department at IIT Kanpur and her favorite professor was Professor Amit Mitra. He had many unique styles that made him the apple of everyone’s eye.

• He would drop emails to students personally at the end of semesters commending them for their performance 
• He would always regrade his papers to minimize any issues
• Once, a mid-semester paper was more difficult than usual. He conducted research on the students who performed poorly despite being regular and asked for their feedback on how to conduct classes in the future. He also discussed the mistakes these students made and the possible solutions.
• He regularly conducted quizzes to evaluate the students on a regular basis.
• He is a very emphatic, approachable, and understanding professor who gives it all to clear the concepts
• His mobile number is public and anyone can contact him

All these distinguish him from other professors and tutors of the department!