"Who is your brother?"
Translation:तेरा भाई कौन है?
'Tumhara' is more formal than 'tera'. Basically, you would use तेरा only with very close friends or family members. It may be seen as disrespectful in a lot of instances so use it with caution. तुम्हारा can be used for most people who are of the same age as you or younger unless you are being very formal with them. It is also used for people regardless of age when you want to show intimacy. The form of 'your' that is even more formal is 'aapka'.
' तेरा ' was not included in the word bank however ' तुम्हारा ' - was. The conjucation for it wasnt covered in any of the lessons prior.
They are all forms of address (think of it like mum, mom,mummy, ma, mama etc). भैया is the most common though there is a lot of regional variation in the preferred form. You will also see भैया spelled a couple different ways because it is not a 'standard word' per se.