Step 1: Fix a starting point using the clearest clue.
Since Debashish sits immediately to the right of Gautam, place Gautam at seat 1 and Debashish at seat 2, moving clockwise around the table.
Step 2: Place Himadri using the opposite seat clue.
Debashish sits directly opposite Himadri, and the opposite seat is 4 places away, so seat 2 plus 4 gives seat 6, meaning Himadri sits at seat 6.
Step 3: List the seats still open.
Seats 3, 4, 5, 7 and 8 remain for Arijit, Biplab, Chintan, Elangovan and Frederick.
Step 4: Apply the Arijit-Chintan opposite clue.
Among the open seats, only seat 3 with seat 7, and seat 4 with seat 8, sit directly opposite each other, since seat 5's opposite seat 1 already belongs to Gautam. So Arijit and Chintan occupy either seats 3 and 7, or seats 4 and 8.
Step 5: Apply the Biplab-Elangovan consecutive clue to test both options.
Elangovan needs to sit exactly one seat to the right of Biplab. If Arijit and Chintan take seats 4 and 8, the leftover seats are 3, 5 and 7, and none of these are consecutive, so this fails. If Arijit and Chintan take seats 3 and 7, the leftover seats are 4, 5 and 8, and seats 4 and 5 are consecutive, so Biplab sits at seat 4, Elangovan at seat 5, and Frederick is left with seat 8.
Step 6: Decide seat 3 versus seat 7 for Arijit and Chintan.
Chintan is not immediately next to Frederick, who is at seat 8, with neighbours at seats 7 and 1. Placing Chintan at seat 7 would put him right next to Frederick, which breaks the rule, so Chintan sits at seat 3, and Arijit takes seat 7.
Step 7: Write out the complete seating order.
Clockwise: seat 1 Gautam, seat 2 Debashish, seat 3 Chintan, seat 4 Biplab, seat 5 Elangovan, seat 6 Himadri, seat 7 Arijit, seat 8 Frederick.
Step 8: Answer the question.
Chintan is at seat 3, so the seat immediately to his right, seat 4, is occupied by Biplab.