Which is best for carrier growth "Web Development or SEO"

Hello Vineet, I think you should decide which stream did u like the most... Did u enjoy developing websites or doing SEO work... Also think from future perspective... It is you who have to decide, what you want to become... 

But still I would personally advice that you go for web development because it has got great scope and great future... SEO is something which I don't have much idea, as to what its future going to be like... But with new technologies coming up, If I would have been at your place, I would have selected Web Development.....

And yes, think before you choose anything as what you like the most and then decide!!! Hope this advice helps you... :) Thanks!!!