I believe real estate would be more meaningful in Pakistan than 'Realtor'. Realtor is an American term, the British prefer to say 'estate agent' or so. Even if the word is understood elsewhere it's not very popular outside America. You probably know that the word Realtor is trademarked and the NAR is actively pursuing infringements. The fact that the TLD is .pk does not change anything about it if the registrant is a US person.
Now to shed some light on the value of any .pk names we need to know if the TLD is popular. I have no idea if .pk is well-established within Pakistan or they are still using .com instead. Abdul can you give us some clues ?
To sum up the name sounds cool at first glance but it does not really fit and I'm sure they are better keywords for the .pk TLD. Just a few observations, I will not quote a $$$ value right now. Good luck.