I have an idea, and requires lot of coding hours , I feel if i start coding , By the time i finish the product will have many more competitors :) , Should i do a Proof of concept and look out for investors ?
I just spent the last year of my life doing a 'proof of concept' and 'looking out for investors'. You'll spend your life always with a sense of insecurity drawn on by the fact that you don't have a real product.
Now, if your favorite Uncle is an investor and absolutely loves you, that's a whole different story. But realistically, make a product, find users who love it, then campaign for them by finding people to invest.
Otherwise you'll lose sight of why you're doing this.