The primary reason for rural-to-urban migration in Tamil Nadu is:

The primary reason for rural-to-urban migration in Tamil Nadu is seeking better economic opportunities. This is because the urban areas offer more jobs and higher wages than the rural areas. In addition, the urban areas have better infrastructure and amenities, such as schools, hospitals, and transportation. This makes it easier for people to find jobs and improve their lives.

Here is a brief explanation of each option:

• Seeking better economic opportunities: This is the most common reason for rural-to-urban migration. People move to the cities in search of better jobs and higher wages.
• Access to education and healthcare: The urban areas have better schools and hospitals than the rural areas. This makes it easier for people to get an education and access healthcare.
• Family reasons: Some people move to the cities to be with family members who already live there.
• Natural disasters: Sometimes, people are forced to move to the cities because of natural disasters, such as floods or earthquakes.