Guild Wars 2

i tried in pvp and i was almost sure that changing attunements affected those sigils which provide effects on weapon change but now i tried in pve and dont see the effects coming up.

Does it work as weapon change or not for sigils?

Yes.

Swapping attunements will proc sigils that have effects “On swapping to weapon”

As will using Ride the Lightning

Though keep in mind that those sigils still have a 9 second cooldown so won’t be able to proc every time you change attunements.