Assalamualaikum. My question is if girl's wali appoints a proxy for marriage does he still have right to give that girl in marriage?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

If the Wali (legal guardian) appoints a proxy to give in marriage a woman under his guardianship on his behalf, this does not waive his right to give her in marriage himself (i.e. act as her Wali in the marriage contract) because he is the original guardian and the principal, while the proxy is only acting on his behalf. Al-Qaraafi said in Al-Furooq: “The Muwakkil (principal, who appoints the proxy) is the primary agent, and the Wakeel (proxy) is the secondary agent.” [End of quote]

Therefore, the principal may remove the proxy and terminate the Wakaalah (proxy authorization). Scholars stated that one of the nullifiers of the proxy authorization is the principal’s action regarding the subject-matter of the proxy authorization. The Hanafi scholar Al-Kaasaani said in Badaa’i‘ As-Sanaa’i‘, in the course of listing the nullifiers of the proxy authorization: “One of them is that the principal himself acts with regard to the subject matter of the proxy authorization before the proxy acts on his behalf … because the proxy becomes unable to act on behalf of the principal since the principal no longer has ownership of the subject matter, so the proxy authorization is no longer valid.” [End of quote]

Allah Knows best.