Which is the best possible sector to fly to Nepal?

Most of the international flight is connected to Kathmandu.

Royal Nepal Airlines is the national flag carrier. Thai Airways operates daily flights between Bangkok and Kathmandu. Other airlines flying in and out of Kathmandu are Qatar Airlines, Gulf Airways, Indian Airlines, Jet Airways, Druk Air, Air China, Biman Bangladesh and Pakistan International Airlines etc.

By Surface

The popular entry points used by tourist to enter Nepal by surface Kakarbhitta