I would wait till you have a good understanding of karate and then consider adding another style. I have over 10 years experience with karate and have been dabbling in taekwondo. It is a challenge to make sure my karate remains pristine. It is very easy to combine them accidentally.The other day I was counting techniques in my karate class and started counting in korean. Or I will mix up my stances, kick with the wrong part of the foot for my technique, etc. However, I have noticed a vast improvement in my kicks and have new ideas to try in sparring. There are definite advantages.

I would just worry that if you are relatively new to karate that it might be a lot harder to learn techniques if you are being taught something similar but different at the same time.

Your logic is wrong. Karate has everything it would ever need, as does every martial arts style..... That is if it is taught as it was originally. People think like you because the style they do or have seen does not teach their whole style. guess I was lucky enough to be taught a complete style. We fought standing, on the ground, ...etc. We learned grappling, striking, kicking, nerve centers, throws, ...etc. Then after years of us just doing what we should do the mma guys come along and start telling us that we don't have this and that in our style. How the heck would they know, they have not studied what I have studied. It is just stubborn ignorance and inflexibility that makes people put down other styles. The, people putting down other style are people that do not have a deep knowledge of what they are putting down. And don't bring up the guys that trained in one school (may have been a good or bad one) when they were a child. no reasonable adult would take the beliefs of someone that trained as a child as being accurate, informative, and impartial.

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Having bounced around with styles due to uncontrollable circumstances, I would advice you to stick with Shotokan as a base for a while longer. There's nothing wrong at all with combining styles, but you should stay until you are pretty competent in Shotokan before you try to learn another. I know from personal experience that learning two different styles can be a pain and you'll have to switch some things for the separate styles and it's much easier when you have a strong base in one art.

At the least, stick with Shotokan until 1st Dan.

5 days per week is just too much. You need a life beyond karate.

Is it smart to practice different styles?

I practice shotokan karate for about a year now and thinking about starting ju-jitsu

Because it contains karate moves as wel.

And i think the different blocks , locks and sweeps related to the defense to those moves will also improve my karate.

I pratice shotokan 3 times a week and ju-jitsu would be 2 times a week.