Step 1: Set the frame.
Six friends sit in a circle facing the centre; we place them clockwise at seats 1 to 6.
Step 2: Place Dinesh and Ashok.
Put Dinesh at seat 1. "Ashok is to the left of Dinesh" means clockwise, so Ashok takes seat 2.
Step 3: Use the Ramesh clue.
Ramesh is between Ashok and Sumit, so Ramesh sits at seat 3 and Sumit at seat 4.
Step 4: Use the Raghav clue.
Raghav is between Sumit and Amit, so Raghav sits at seat 5 and Amit at seat 6.
Step 5: Locate the right of Raghav.
Facing the centre, a person's right is the counter-clockwise neighbour; for seat 5 that is seat 4.
Step 6: Read seat 4.
Seat 4 holds Sumit.
\[ \boxed{\text{Sumit}} \]