Question

can three vectors not in one plane give zero resultant

Answer 1

To give zero resultant, the three vectors should form a triangle like the following

now, you have to think.. whether you can make a triangle which does not STICK to one plane..

if you can do that, then its possible.. what do you think?

Answer 2

Imagine attaching two strings to a ball and
then trying to hold it in position against the third
force, gravity.