Yes it's very important.

Based on JEE point of view .

Vector and 3 d geometry cover almost 6-7 percent of maths paper 

Also for all other entrance exams too.

So focus solve problems topicwise and remember quality is important than quantity.

Also 

You need good understanding of vector to study physics.

It's crucial

Hi Arshan! 

Greetings! 

Skipping vector and basic math is like . . . I DON'T KNOW WHAT !!

They are very important chapter. And easy and interesting too . They will help you in ur further chapters … In whole of mechanics part . .. . . especially the representation of the vectors on the 3D axis using i,j and k . Relative motion , rain man problems , and river boat problems are directly related to vector . it is very important in projectile motion and formula proofings . take things simple … And explore the beauty of vectors . . .

Please upvote if this was helpful to you. 

All the best !!