The Monomyth

I never really thought of the Monomyth in terms of Darjeeling until now, really.
But I don't think, in the context of this story, you can really apply one whole monomyth to all the characters. Or rather, you can, it's simply that it is perceived differently by each character:

Loss/Lack: The beginning of the romantic triangle between Aloka, Sujata, and Pranab, where essentially the sisters' love for Pranab tears the foundations of the family apart. Essentially, when all three of these characters are either exiled or flee to North America, they have lost many connections with their home back at Darjeeling when they are forced to start a new life. This could very well be part of the journey however, since it takes a lot of setup to get to this "breakdown point."

If considering this stage of the monomyth to be a form of lack, then the "lack" the three characters go through is maturity or an ability to understand each other genuinely. Sujata is the black sheep, and lacks the respect and acknowledgement that her sister receives. Aloka's lack is her inability to understand her sister's struggles of always having to be in the shadow, and in a sense, she lacks indepence-- both sisters lack independence. Nina's journey for me is all about bringing Aloka and Sujata closer together, even though I find her, through all her mistakes, to be a static character. Even still, her lack would be, then, not being able to keep Aloka and Sujata together?

Journey:
Not including the exile and the immigration, which has a debatable position, the journey for Nina is trying to make amends for the tragedy of Aloka, Sujata, and Pranab's dissipated love triangle, which has also severed some of their relationships. Sujata's journey would be coping with life in Victoria then returning to Darjeeling to make her name known and to regain respect that she did not previously receive, and to be able to face Aloka, her sister and rival, after a long period of alienation. Aloka's journey is trying to overcome the shadow of the "ideal woman's glasses" as she blends into the world of New York but also faces divorce and being able to face her Indian relatives back at home. Pranab's journey is trying to figure out whether he should let go of the past and his status in order to achieve glory.

Test:
For Aloka and Sujata AND Nina, the test was probably the channer payesh  making scene. Period. Or, that could be expanded to Aloka's final confrontation with Pranab and Sujata's final meeting with Mreenal when they stand up to their men and tell them that they have or can move on and do not need a man bringing them down.When Aloka stands up to Pranab in the cafe Pranab receives his test of whether he is willing to pick himself up from an impossibly dark hole.

Return:
Aloka and Parnab both return separately to New York to continue or restart their lives refreshed and renew, their relationships fixed or resolved, likewise with Sujata, who has now returned home to take care of the family tea business.