cluster "nd/nt"

PIE radicals for wind= *ue, for "see"= *ueid, *uid"

Actual forms in IE languages:

wind: *ue
Gothic "winds", Latin, "ventus"
Greek "afeni", Sanskrit "vati" but too "vant "

to see: *ueid, *uid
Gothic "witan", Latin "video"
Greek "eidon", Sanskrit "veda "

I wonder about the cluster "nd/nt". If this should have been just in
"European" area one will think this cluster is an innovation of European
IE languages even if missed in Greek (but in Greek is "n" too)
But there is in Sanskrit too, that will mean what? Separate innovations
or a common way of developing the language until a given point?
And how did this "n" appeared ?

Regards,

Alex