He was the father of Bashir Ahmad Misri, the Ahmadi who accused Basherruddin Mahmud Ahmad of sexual crimes and etc.  Sheikh Abdur Rehman Misri , was a very devoted companion of Hazrat Masih Maud AS. He was converted to Islam from hinduism, specifically from the Aryas.  Mirza Masroor Ahmad mentioned a brief account of the life of Shaikh Abdur Rehman Misri here:

During the Khilafat of Maulana Noor Ud Din, Shaikh Abdul Rehman Misri sahib went to Egypt (MISR) to attend AL-AZHAR UNIVERSITY. This is how Shaikh Abdul Rehman Misri sahib came be known as MISRI. When he returned from Egypt, Maulana Noor Ud Din sahib had already passed away and Movement was split in two groups. The split was based on the belief of Mirza Mahmud Ahmad who claimed that Mirza Ghulam Ahmad sahib (nauzubiliah) claimed to be prophet and is equal in rank to Holy Prophet Muhammad saws. Intellectuals of Movement moved to Lahore and started their anjuman called AAIIL.

He was a very learned scholar, a most trusted follower of Mirza Mahmud Ahmad, the Khalifa Sani.  He was the Head Master of Talim-ul-Islam High School in Qadian.  MIrza Mahmud Ahmed used to appoint him qaim maqaam Amir-e-Maqami when he was away from Qadian.  Abdul Rahman Misri sahib accused Mirza Mahmood Ahmad sahib for sexually assaulting his young son, Hafiz Bashir Ahmad Misri, and requested him to either set up a Commission of Inquiry, or face a challenge of Mubahalah to clear his name. Mirza Mahmood Ahmad sahib refused to either request and turned against Misri sahib.

After leaving Qadian, the Lahori-Ahmadis hired him as a Mullah and etc, he began reminding Qadiani-Ahmadis of his stature with MGA and his marriage, which MGA had arranged.

He also helped Mumtaz Ahmad Faruqi write the famous Truth Triumphs book (1965), which exposed the Qadianis.

Interestingly in Urdu section of said book in introduction Mumtaz Ahmad Faruqui sahib writes on page 5:

“””Here I want to thank Maulana Shaikh Abdur Rehman Misri sahib and Maulvi Abdul Mannan Omar sahib M.A. They read manuscript of this book and gave helpful advice, and made some corrections. May Allah SWT reward them.”””

He wrote many books, they exist on the Lahori Website, see here:

Sheikh Abdur Rehman Misri: