The correct answer is option 'C' - Nilgiri Hills.

The Eastern Ghats and Western Ghats are two mountain ranges that run parallel to the east and west coasts of India, respectively. They meet at the Nilgiri Hills, which are located in the southern part of the Indian subcontinent.

The Nilgiri Hills are a part of the larger Western Ghats range and are situated at the tri-junction of the states of Tamil Nadu, Kerala, and Karnataka. This region is known for its breathtaking beauty, lush greenery, and rich biodiversity.

Here is a detailed explanation of the answer:

1. Eastern Ghats:
The Eastern Ghats are a discontinuous range of mountains and hills that run along the eastern coast of India. They extend from West Bengal in the north to Tamil Nadu in the south. The Eastern Ghats are relatively lower in elevation compared to the Western Ghats, with an average height of around 600 meters.

2. Western Ghats:
The Western Ghats, also known as the Sahyadri Mountains, are a continuous mountain range that stretches along the western coast of India. They run parallel to the Arabian Sea and cover a distance of approximately 1,600 kilometers. The Western Ghats are higher in elevation compared to the Eastern Ghats, with peaks reaching over 2,400 meters.

3. Nilgiri Hills:
The Nilgiri Hills, also called the Blue Mountains, are a part of the Western Ghats. They are located in the southernmost part of the Indian subcontinent, at the junction of Tamil Nadu, Kerala, and Karnataka. The name "Nilgiri" translates to "blue mountains" in the local language, referring to the bluish haze that envelops the region.

The Nilgiri Hills are known for their stunning landscapes, dense forests, and numerous tea and coffee plantations. They are home to several wildlife sanctuaries, national parks, and biosphere reserves, making them a significant biodiversity hotspot.

The meeting point of the Eastern Ghats and Western Ghats at the Nilgiri Hills creates a unique geographical and ecological transition zone. This convergence of two major mountain ranges contributes to the region's climate, rainfall patterns, and the distribution of flora and fauna.

In conclusion, the Eastern Ghats and Western Ghats meet at the Nilgiri Hills, which are located in the southern part of the Indian subcontinent. This region is known for its natural beauty, diverse ecosystems, and rich cultural heritage.