Which of the following districts is not part of Rohtak division?

Concept

Haryana is administered through revenue divisions: each division is a cluster of districts placed under a Divisional Commissioner for revenue and general administration. The state currently has six such divisions — Ambala, Faridabad, Gurugram, Hisar, Karnal and Rohtak — and every district belongs to exactly one of them. A question of the form "which district is not part of division X" is therefore settled by recalling the roster of division X and testing each offered district against that roster.

Application

1. Recall the roster of Rohtak division: Rohtak, Jhajjar, Sonipat, Bhiwani and Charkhi Dadri.

2. Test Jhajjar against that roster: it is listed, so Jhajjar lies inside Rohtak division.

3. Test Sonipat against that roster: it is listed, so Sonipat lies inside Rohtak division.

4. Test Bhiwani against that roster: it is listed, so Bhiwani lies inside Rohtak division.

5. Test Rewari against that roster: it is not listed. Rewari is grouped with Gurugram and Mahendragarh under Gurugram division.

6. Exactly one of the districts offered falls outside Rohtak division, so Rewari is the district the question asks for.

Cross-check

Reading the two divisions side by side makes the split explicit:

Geographically this matches the state's layout: Rewari sits in the Ahirwal belt of south Haryana and is supervised from Gurugram, while the Rohtak division covers the central-western districts around Rohtak. The district that is not part of Rohtak division is therefore Rewari.