Congrats on your new job. For elders I think you cannot bring her on RP if she is above 60 and initially to sponsor family there are requirements like salary should be above 10,500k, house rental agreement and bank statement and the list goes on. But if you are joining one of biggies they will take care of the visa process for family (mostly they do). If you mother is above 60 then you can only bring her on family visit (some times very difficult to get for elders) valid for 6 months. If you can, put a request to company's HR to provide you the details and they might be able to give a clear answer if it will be your responsibility or they will help.