Man pages matching name rngtest in section 1:

rngtest.1.en	debian 10 / rng-tools
rngtest.1.en	debian 10 / rng-tools-debian
rngtest.1.en	debian 10 / rng-tools5
rngtest.1.en	debian 11 / rng-tools-debian
rngtest.1.en	debian 11 / rng-tools5
rngtest.1.en	debian 12 / rng-tools-debian
rngtest.1.en	debian 12 / rng-tools5