Hi melikcankanat,
A CAT is really a 'measuring device' - when used correctly, it will give you a realistic score and help define your strengths and weaknesses, but it will NOT help you to fix any of those weaknesses. To raise your scores, you have to learn the necessary Tactics and put in the proper practice and repetitions. The CAT will show you whether your studies are helping you to improve or not. In addition, the process of taking (and reviewing) a CAT requires a significant amount of energy and effort - and takes time to 'recover' from. This is one of the reasons why you typically shouldn't take more than 1 CAT per week - and your last CAT should be taken about 1 week before Test Day. Going forward, you really shouldn't take more than 1 FULL CAT per week.
The variations in these results are likely due to a mix of lucky/unlucky guesses, little mistakes (that you either made or did not make on individual Tests) and any time you saw any 'repeat' questions (since seeing any prompts that you already know the answer to will likely lead to an 'inflated' score result). In addition, it's not clear how rigorous you were about making sure that you took these CATs in a fashion that matches-up with how you will take your Official GMAT. All that having been said, these overall results imply that your content knowledge is good and your likely 'ability level' is probably right around a 700.
If you're not planning to apply until Round 2, then you have plenty of time to continue studying. Since you know the specific Schools that you plan to apply to, you would likely find it beneficial to speak with an Admissions Expert about your overall profile and plans. Those Experts should be able to answer your Admissions questions and help define the specific areas of your profile that could use some improvement. There's a Forum full of those Experts here:
https://gmatclub.com/forum/ask-admissio ... tants-124/If you're interested in some additional study materials, then I'd be happy to offer some suggestions.
GMAT assassins aren't born, they're made,
Rich