Etiquette for a female PhD student to reject her male supervisor's invitation to meet outside of work The role of supervisor is a key role. The relationship between the supervisor and the students should be healthy. 

In this context, in India, there is a lot of difference between male and female students. If a male supervisor frequently holds meetings outside of the workplace,  male students can participate without any fear while female students cannot. 

How does a female student reject the invitations of a male supervisor to meet outside of the workplace (such as in the supervisor's home)? The purpose of the invitation is to discuss the developments or updates in research. 

Many incidents like 1,2,3 etc., have occurred and hence female students have to think about their safety but at the same time they still have to work around the supervisor's workload. (He may not get time during his working hours to review his scholar's progress.)
While I know India is not the US (or any other country I am familiar with), but some norms should be universal and a student should not have to subject themselves to things outside the norm. Something like


  Dr. Smith, it is nothing against you, but I do not think it sets a good precedent for us to meet under those conditions. Is there a time we can have the meeting at the university?


Now, Dr Smith may get very mad and take it out on you, but if they are the type of person to do that, do you want them as a supervisor, and more importantly, do you want to meet them alone at their home.