I would add "the" before Himalayas.
Student or Learner
I am not sure if my sentence sound natural and if I punctuated it correctly. Would you please correct my mistakes?
The old woman brewed me tea, which she said was rare and comes from Himalayas.
I, too, would add the article. I would probably also make the tenses agree in the second half. Either "it is rare and comes from" or "it was rare and came from". I prefer the present tense version.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.