I referred the DB and agent compatibility matrix and couldnt find any thing about Lotus notes 9.0.1 32 bit being supported.
Is this supported on windows 2008 R x64 OS with any NBU Version.
Compatibility lists are always updated, if you do not find the compatibility you desire; consider its not supported.
In your case Lotus notes 9.0.1 32 bit is not supported to run on Windows 2008 R X64. However, i see SLES 12 is supporting Lotus Notes 9.0.x 32 bit db.