Please tell me whether is it necessary to eat supplements for a bodybuilder. Abs and Muscles etc, can it build as fast as when supplements are taken?
It's not a very specific question, it's basically like asking whether it's necessary to wear running shoes to run a marathon.. the answer is no, but it's a lot harder with leather boots, and even harder without shoes. Unless you can't afford the running shoes, or you made some sort of silly bet, there's really no point in going barefoot.
Also, understand that bodybuilding supplements a not one generic product; supplement is a very broad term that includes many different substances, all of which have unique features. Some supplements are effective, some of them are a waste of money, but talking about supplements in general does not make a lot of sense. It's like asking whether food needs spices. Well, no, not necessarily, but so what?
To answer your question though, it's definitely possible to build muscle as a bodybuilder without any supplements.
First, if you take supplements to mean steroids and such, these are definitely not necessary, and are in fact dangerous. The notion that all or most bodybuilders take steroids is a myth.
Second, if you take supplements to mean protein shakes, weight gainers, and so on, the reason these are useful is they allow you to consume a lot of nutrients very efficiently. They save you time since you have to prepare less food, and it takes less time to consume them. They also enable you to eat more than your appetite would allow. They contain the same nutrients as actual food, only in concentrated and properly balanced form. There is nothing inferior about them compared to actual food; eating "natural food" is not invariably better for your body, although many people falsely think so.
Is it possible to gain muscle without protein shakes, weight gainers, and all the other stuff that falls into the category of "food replacement"? Well, yes, of course. But you'll have to stand in the kitchen all the time (or have someone do it for you), prepare truckloads of food, and spend a lot of time eating every day. Often it will be hard to get all that food inside you, especially at the beginning. Instead of quickly gulping down a vanilla-flavored drink, you'll have a big heap of chicken and rice in front of you. But no, it's not impossible.
Third, if you take supplements to mean creatine monohydrate, L-carnitine, fatty acid supplements and all those other fancy products, they are by no means necessary. All these do is give you a slight edge, if that. They are as necessary as the runner's sweatband, or the garlic in your food. Some swear by them, but everyone agrees you can live without them.