Scar is Simba's...
Uncle
Mufasa is Scar's...
Brother
Mufasa is Simba's...
Dad
Mufasa is Kiara's...
Grandpa
Kiara is Nala's sister.
No
Nala is Simba's aunt
No
Simba is Kiara's....
Dad
Sarabi is Simba's grandma.
No
Sarabi is Simba's...
Mom