I have lots of sikh friends and have dated punjabi guys who grew up in England, Scotland, India and the usa.
It depends how traditionalist & religious, whether parents are willing to accept change affecting future generations and if there is a history of hereditary illness or violence within the family.
But if your family are violent, very caste conscious, religious vegetarians, vociferously hostile towards alcohol, have a tradition of arranged marriages within the family or support khalistan- don't take the risk of letting them know about your private life.
Plenty of friends have dated or married people of other caste, racial and religious backgrounds.
I know many sikh families who are supportive of interfaith relationships and happy to welcome partners of all castes, nationalities and religious beliefs.
Often families with a history of health problems are the most open minded about young relations dating and choosing interfaith marriage with people of very different backgrounds.
But I also volunteer with charities supporting the survivors of rape, forced marriage and honour abuse.
I've supported many people whose traditionalist families discovered their friendships or romantic relationship with people of other caste, religious or racial backgrounds that disinherited them or turned violent.
Plenty of survivors whose relatives disowned them then mounted a vicious hate campaign based on vitriol and lies but no violence too.