The planners design a tramway for a road with around 4000 passengers/hr per each direction in peak hours . Just I want to examine the possibility of implementation of BRT mode instead of Tramway.
The short answer is yes and by a large margin. Capacities up to 35000 passenger per hour and direction and even more have been OBSERVED in Transmilenio BRT. See the BRT Planning Guide: https://www.itdp.org/wp-content/uploads/2014/07/52.-Bus-Rapid-Transit-Guide-PartIntro-2007-09.pdf
4 000 per hour seems to be a low value (for example France is more around 5 000 or 6 000). If you want to compare with tramways, the level is below for BRT (depending of type of BRT) but the crucial difference is in terms of cost (fixed and variable costs).
You can find information on BRT in reading Finn et al. (2010), Bus with a high level of service: The european BRT concept, Tranportation Research Board.
Based on your question, it's yes and could be more. It also depend on the vehicle capacity, headway, roadway, stops, period of the day, etc. You may as well check http://www.nbrti.org/index.html and search for relevant materials in the news letter.