Srila Prabhupada: Kanistha-adhikari means he must be a brahmana.
That is kanistha-adhikari. The spiritual life, kanistha-adhikari, means
he must be a qualified brahmana. That is kanistha. What is esteemed as
very high position in the material world, brahmana, that is kanistha-adhikari.
(Srila A.C. Bhaktivedanta Swami Prabhupada. 770214r2.may - 14th February
1977. Mayapur, India.)
...sometimes, and quite wrongly, the kanistha adhikari is looked down
upon in a condescending manner. Here Srila Prabhupad clearly defines what
is the basics for a kanistha adhikari.