If you work for a big software company and now have a task to hire a react developer, it is not as complicated as you think. You have numerous ways of completing this task successfully and to the mutual satisfaction of all stakeholders.
First of all, advertise in your local market. Local IT communities, Fb groups, job sites provide you with a pool of interested candidates. The React.js framework is trendy, so it’s a big chance that you’ll get enough candidates to be interviewed - there are a lot of developers knowledgeable in the needed area of expertise.
If the salary expectations exceed your company's budget, you can always proceed with an offshoring procedure.