'of which did' is not grammatically correct.
You can use 'of which' to refer to a previously mentioned noun or phrase. For example, "She bought a car, of which she was quite proud."
Speaking of which, did anyone see the 50km walk earlier?
Speaking of which, did he get the Easter lilies?
He appeared in only three Broadway shows, none of which did well.
But there were also thousands of pages of trivia, some of which did harm.
Affected towns, many of which did not spray last year, will have to pay for spraying.
Roach subsequently formed other ensembles, many of which did not include a pianist.
Speaking of which, did you know that traffic fatalities go up markedly in summer?
(Oppenheimer counted sixty-two planned screenings throughout the country, the majority of which did not get shut down).
This year it lists 14 vehicles in this category, more than half of which did not exist before 1997.
The study's authors cited results for two groups, one of which did not remain with the trial until its end.
When the police searched Ms. Toth's bedroom at the Reids' home, they unearthed reams of bookkeeping, most of which did not belong to her.
