I'm trying to build a hexapod with several new capabilities and all the features used are not my original creation but the idea of combining them together to form a bot is my idea, and there is no bot that can do what mine does (as far as I researched). So will this be considered as novelty or just some new addon to the existing technology???
Determining whether or not an innovation is novel is usually based on a novelty search. This means performing a comprehensive search of the prior art, which includes not only existing products, but also patents, patent applications, and other published literature.
Many patents and applications never result in an actual product, so there may be prior art out there that describes your innovation without the actual robot ever being constructed.
Typically, combining known elements together is challenging to patent, unless there is a non-obvious inventive step required to combine them, or the combination yields some sort of unexpected result.
As some other answers have suggested, there are two major requirements that are relevant to your question. The two requiresments are: novelty and nonobviousness. (Nonobviousness is a U.S. term; in Europe this is referred to as inventive step.) To earn a patent, your invention must pass both tests. In your case, the invention passes the test of novelty because there is no single publication or no single device that describes/possesses every single feature of your invention.
Now let's consider the test of nonbviousness. Let's say your invention consists of components A, B, C, and D. The Patent Office finds a prior patent ("patent 1") that describes A and B together. They also find an earlier patent ("patent 2") that describes C and D together. If they get lucky, they'll find a third prior patent ("patent 3") that suggests combining B and C (or A & C, or A, B, & D, etc.). On the basis of patents 1, 2, and 3, the Patent Office will reject your patent application for being an obvious invention.
So what makes an invention obvious? All of the components making up the invention have been described in the prior patents, and there's a known reason to combine them together. But even if the Patent Office never finds Patent 3 (which suggests the combination), the Patent Office can still reject your application and make this argument that the invention is obvious. In place of Patent 3, the Patent Office can simply assert (and often does) that "it would be obvious for someone with an ordinary level of skill in this field to combine Patent 1 with Patent 2 because doing so would have an obvious benefit."
As a general rule, combatting nonobviousness rejections can be difficult, but they're certainly not impossible to overcome. There are many ways to approach this hurdle: you can defeat a nonobviousness rejection by showing that experts taught away from / discouraged the combination, by showing that the combination had an unexpected result, or by having an expert in the field submit an affidavit stating on record that it wouldn't have been obvious to combine Patents 1 & 2, etc. Consulting a patent attorney, patent agent, or patent expert is the best approach. The particular strategy worth pursuing depends on the facts of the case, and it's hard to be more specific than this without detailed information about the invention.
You do have something that might be beneficial as you and your attorney formulate a strategy: you have unique functionality. In most cases, unique functionality is not by itself enough to earn a patent. For example, if I discover that chairs can be used as fuel for nuclear fusion, then that's great, but it doesn't mean I'm allowed to go patent a chair. A new use or functionality for a device does not make an old device eligible for patent protection. But depending on the details, a patent agent/attorney might be able to write that unique functionality into the application as a structural feature (or tie it closely to a structural feature), which could improve your chances of earning a patent. This could be something to discuss with your patent agent or attorney.
In summary, the answer to your question depends on the specific facts of your case, but in general, attorneys do have a variety of ways to overcome obviousness.
I am no expert, and this response is for informational purposes only and not for the purpose of providing legal advice. You should contact your attorney or legal expert to obtain advice with respect to any particular issue or problem. Laws can differ dramatically from country to country, state to state, and technology field to technology field.
If the all the characteristics of your invention are not found in one prior art single document then your invention is considered new. However, it might not be considered inventive if the combination of all these characteristics would be considered something straightforward to the skilled man in that technology area. As you might suspect this has to be seen on a case to case basis whether or not the combination of all the characteristics of your invention would be arise naturally when comparing documents from the know prior art. You can check the site of the USPTO or the EPO for more details on this matter.