Which river does not constitute a part of internal drainage system?
The river which becomes extinct on land or drains its water into a lake forms internal drainage system. Examples of the rivers which constitute internal drainage system are Ghagar, Banganga, Kantali, Saabi, Ruparail, Menda etc. Among the given options, the river which does not contribute to the internal drainage system is Banas. This river falls under Bay of Bengal Drainage system.