There is no limit on how many projects you can enter into our contests.
There is also no limit on how many different projects you can enter per category or format.
So, to take an extreme example, you might have 10 projects and enter 7 of them in the TV Script category (if that's what they are, TV scripts) and the remaining 3 in the feature film category.
Further, your 3 feature film scripts might all be Action & Thriller projects - in which you'd enter all 3 in to the Action & Thriller Feature Film Category.
As this article explains, the only area where we cap submissions in this respect is in terms of submitting the same project to multiple categories.
You can only enter the same project in a maximum of 3 contest categories and obviously the categories you select can't crossover, format-wise (your feature film script which you've paid extra to enter in Action & Thriller / Comedy / Lo-Budget can't also be entered in TV Drama, for obvious reasons).