I currently still provide services to a small clientele whom I extended an invitation to my home for their appointments.
Welcome to the forum, SMAKK.
It needs 'to' before 'whom' to be grammatical. However, three tos in the sentence is one too many.
It would be better as
I currently still provide services to a small clientele whom I invite to my home for their appointments.
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Please note that a better title would have been A small clientele.
Extract from the Posting Guidelines:
'Thread titles should include all or part of the word/phrase being discussed.'