If you want to visit members of your family in the UK, you can apply to come here as a family visitor (or as a child visitor if you are under 18).

Family Visitor
Family Visit Visa to the UK will be granted to a person who is living outside the UK and who wishes to come to the UK genuinely to visit their family members who are present and or settled in the UK. The leave that will be granted for family visitor visa will not extend beyond 6 months period. There are specific definitions within Immigration Rules as to who would be defined as family members.

Child Visitor
If you are below 18 years old and you wish to visit the UK to visit family members who are settled in the UK then you should apply for a Child Visitor Visa to the UK. The leave that will be granted for a family child visitor visa will not extend beyond 6 months period. There are specific definitions within Immigration Rules as to who would be defined as family members.