well,to find the hybridization state of any compound all you have to do is predict the sigma bonds and lone pair in central atom.

ex.

CO₂   .b.=2   l.p.=0.   h.s.=2+0=2=sp

XeF₆  .b.=6   l.p.=1    h.s.=6+1=7=sp₃d₃

BH₃NH₃   for B  .b.=4 l.p.=0   h.s.=4+0=4=sp₃

for N   .b.=4  l.p=0 as the lone pair is shared with B a sigma bond is formed and lone pair is lost. h.s.=4+0=4=sp₃.

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