Is there a way one could learn about the local funeral customs (irrespective of the religion of the deceased) while traveling through a country ?
In NT, Australia how could one go about learning the funeral customs of Aboriginal/Indigenous tribes ?
Approaches to death can differ significantly among Aboriginals. Your best bet would be to go to a good Aboriginal museum or cultural centre but some Aboriginal people believe that people effectively cease to exist after death so will not discuss anything related to it.
The Aboriginal Australia Culture Centre in Alice Springs has a page that includes information about ceremonial behaviours, so I'd suggest that as a good and accessible starting point. I haven't visited it myself to give you a first-hand report.