As of now, 15% is the only option however since there is a double taxation treaty, you can reduce your tax since a certain amount of tax was already deducted in the US. To avail benefits under the Double taxation treaty, you need to collect the 1042-S form that Udemy sends to instructors and give it to a CA. Not all CA's are familiar with this, so you might have to look for a consultant.
... View more