The correct answer is: Dimapur (Nagaland).
Dimapur is the nearest major railway station to Manipur. It is located in the Nagaland state of India. The railway station is well-connected to other major cities in India, such as New Delhi, Kolkata, and Chennai. It is also well-connected to other major cities in the North East, such as Guwahati, Shillong, and Imphal.
The other options are incorrect because they are not major railway stations. Silchar is a small town in the Assam state of India. It is not a major railway station. Guwahati is a major city in the Assam state of India. It is a major railway station, but it is not the nearest major railway station to Manipur. Kohima is the capital of the Nagaland state of India. It is not a major railway station.