As per the GST law company can avail credit for the taxes paid on expenses for categories like Hotel, cabs, flights, etc.
There is no provision in the expense report to capture GST information when the expenses are recorded. To use the input taxes as credit it should be recorded first in the system.

Repro steps:
1.Create a new Expense Report(Expense management>My Expenses>Expense Report)
2.Create New Expense line.
3. Fill details for Expense Category.
4. Fill the Amount.
5.Change view to details for Tax details.