Where is Mount Thullier located in India?

India's offshore islands fall into two distinct physiographic groups: the hilly, forested Andaman & Nicobar Islands in the Bay of Bengal, whose peaks can rise several hundred metres, and the low coral atolls of Lakshadweep in the Arabian Sea, which rarely exceed a few metres above sea level. The Western Ghats and the Shiwalik Range, by contrast, are mainland mountain belts and are not islands at all.

Mount Thullier (sometimes transliterated Thuillier) is a peak on Great Nicobar Island, the largest and southernmost island of the Nicobar group in the Bay of Bengal. It is the highest point of Great Nicobar and one of the tallest points across the whole Andaman & Nicobar archipelago, reflecting that island group's hilly, forested terrain — quite unlike a mainland range or a low coral atoll.

• Western Ghat is a mainland escarpment running along India's west coast from Gujarat to Kanyakumari (Tamil Nadu), separating the coastal plain from the Deccan Plateau — it carries no peak by this name.

• The Shiwalik Ranges of the Himalayas form the outermost, geologically youngest sub-Himalayan foothill belt across northern India, unrelated to the Nicobar Islands.

• Lakshadweep is a group of low coral atolls in the Arabian Sea, with terrain that stays within a few metres of sea level and cannot host a peak of this height.

Mount Thullier therefore lies on Great Nicobar — matching RSSB's official Shift-1 answer key for this question.