If you are asking yourself, what is the equivalent of the Notes 10.0.1 Client, from a security und patch standpoint, in 9.0.1 release, that would be the 9.0.1 FP10 IF6 version including the latest JVM Update, 1.8 SR5FP21, released in October.
JVM Version used in IBM Notes 10.0.1 Client Version.