We would recommend reporting any form of discrimination in an official complaint to your university and ask your local students’ union for support.  
We say this as most external organizations won’t get involved until the university has had an opportunity to address the issue.  
You can then get in touch with the OIA to take the complaint further with an independent external body. 
You can also get some advice from the Equality Advisory and Support Service their helpline advises and assists individuals on issues relating to equality and human rights. 
For instance, please find here the information provided in this recent report from the Equality and Human Rights Commission around racial harassment.
You can also report a hate incident and get support by phoning the Stop Hate UK, phone line on 0800 138 1625, available 24 hours a day, or by using the online webchat service. 
Additionally, you can report a hate crime to your local police.