Ashrafs, Ajlafs and Arzals
In theory Islam does not recognize castes.
But practice among Indian Muslims is very different from theory
Some of the backward or lower-caste Muslim castes include Kunjra, Dhobi, Halalkhor, and Kalal (so called ranki involved in the profession of wine selling and making.)
The upper caste Muslim castes include Pathan, Muslim Rajput, Turk, Sheikh, Khan, Syed, Rizvi, biradri, and Malik.
Ansari, Qureshi, etc are intermediate castes among Muslims,. like Hindu OBCs
Genetic data has also supported this stratification.
The report commissioned by the government of India and released in 2006, documents the continued
stratification in Muslim society.
While in the mosque all Muslims pray together, but when it comes to marriage their attitude is very different, and most ashrafs ( upper caste Muslims ) will not marry Muslims of the lower castes.
I have many Muslim friends who tell me with pride that they are Rajputs. I know of one Rajput Muslim convert family in Banda, U.P. whose girl fell in love with a dalit young man who was a Magistrate. He converted to Islam to marry her, but the girl's family members told him " humne mazhab badla hai, jaat nahin " and told the young man to breaak of ties with the girl or they would kill him. The poor fellow was terrified, and got himself transferred to another district.
I know of a Syed girl who had been my daughter's classmate since childhood. When she had grown up I went to her father, a doctor, and told him I knew of a young Ansari boy from Bhadohi ( the carpet belt near Varanasi ) who was a multi millionaire, and suggested a match. They told me " Hum chamaron mein shadi nahin karte ". I was shocked, and said that I thought Islam does not recognize caste. His wife told me " Bhai saheb, hamein apni biraadari mein rehna hai "