De or het basketbalfederatie?

The correct Dutch article is:

de basketbalfederatie

Rule Words ending in -tie and -sie: almost always de. See the rule

How to use basketbalfederatie

the basketbalfederatiede basketbalfederatie
this basketbalfederatiedeze basketbalfederatie
that basketbalfederatiedie basketbalfederatie
our basketbalfederatieonze basketbalfederatie
your basketbalfederatiejouw basketbalfederatie
every basketbalfederatieelke basketbalfederatie
which basketbalfederatie?welke basketbalfederatie?
a big basketbalfederatie / the big basketbalfederatieeen grote basketbalfederatie, de grote basketbalfederatie