stiffening ring database

Dear PVElite Users and moderators,
I'm struggling with the European Database for sections used as stiffening rings.
Not clear to me which is the source, for example I see "Section name: TR152X101.3", but I cannot Identify it according to any standard.

Do you have some hints?

Thank you
Federico Freschi

It is a "T" section (or half "I" section). I'm not familiar with, it seems to be an Indian standard.