Bihar is often considered part of East India because of its geography, but it has been included in the Plains to club it with Uttar Pradesh and Madhya Pradesh, to which it is culturally closer.
From Bangladesh, there are a number of land entry points to India. The most common way is the regular air-conditioned, and comfortable bus services from Dhaka to Calcutta/Kolkata via Haridispur (India)/Benapole (Bangladesh) border post. Bus companies 'Shohag', 'Green Line', 'Shyamoli' and others operate daily bus services under the label of the state owned West Bengal Surface Transport Service Corporation (WBSTSC) and the Bangladesh Road Transport Corporation (BRTC). WBSTSC operates buses from Calcutta every Monday, Wednesday, and Friday while from Dhaka the days leave on Tuesday, Thursday, and Saturday. BRTC also operates the buses from Calcutta and Dhaka on the same days. The normal journey time taken by these busses is around 12 hours with a oneway fare of Rs. 400-450 or BDT(Taka)600-800, roughly USD 8-10.
Another daily bus service by 'Shyamoli' and others under the BRTC label from Dhaka connects Siliguri, but the busses in this route do not cross the Changrabanda/Burimari or Burungamari border post. Rather, passengers reaching the border have to clear customs, walk a few hundred yards to cross the border and board the awaiting connecting busses on the other end for the final destination. Ticket for Dhaka-Siliguri-Dhaka route costs BDT 1600, roughly USD 20-25 depending on conversion rates. Tickets are purchased either in Dhaka or in Siliguri.
Other entry points from Bangladesh are Hili, Chilahati/Haldibari, Banglaband border posts for entry to West Bengal.