The correct answer is Option 1: Andaman Islands.

The Andaman Islands are a group of islands located in the Bay of Bengal, which are a part of India`s Union Territory of Andaman and Nicobar Islands. These islands are known for their rich biodiversity and are home to many unique and endemic plant species. The discovery of a new and distinct species of banana plant with specific characteristics, such as attaining a height of about 11 meters and having orange-colored fruit pulp, aligns with the unique and diverse flora found in the Andaman Islands.

The Andaman Islands are known for their tropical rainforests, which provide favorable conditions for the growth and discovery of new plant species. The islands have a moist climate with high rainfall, which supports the growth of diverse plant species. The isolation and distinct ecological conditions of the Andaman Islands have resulted in the evolution of many unique and endemic species, including plants.

Furthermore, the Andaman Islands have been a hotspot for scientific research and exploration due to their rich biodiversity. Several scientific expeditions and studies have been conducted in the region, resulting in the discovery of new species of plants and animals. Therefore, it is highly likely that the new species of banana plant with orange-colored fruit pulp was discovered in the Andaman Islands as part of ongoing scientific research and exploration efforts.

In addition to the above points, it is important to note that the other options - Anaimalai Forests, Maikala Hills, and tropical rainforests of northeast - are not known for the discovery of banana plants with orange-colored fruit pulp or the specific characteristics mentioned in the question. These regions may have their own unique flora and fauna, but they are not specifically associated with the discovery of the new species of banana plant mentioned in the question.

In conclusion, based on the available information and reasoning, the correct answer is Option 1: Andaman Islands. The Andaman Islands are known for their rich biodiversity, tropical rainforests, and ongoing scientific research and exploration efforts, which make them a likely location for the discovery of a new and distinct species of banana plant with unique characteristics as described in the question.