What is the difference between the following sentences?
I'll be in later home tonight.
I'll be in late home tonight.
I'll be late home tonight.
In all sentences the word "home" seems out of place, or rather superfluous. Now, without it
I'll be in later tonight.
means that some time this evening, after some time passes (from now), people will be able to find me "in", which means "inside", "at home", or at some other place according to the context.
I'll be in late tonight.
means that this evening (i.e. before the day is over, i.e. before midnight) people will be able to find me "in" (see previous explanation), but that will happen past the time that was agreed upon.
I'll be late tonight.
means that this evening I will miss the time that was agreed upon (whatever that is), to do what I was supposed to do at that time.
As you see the last sentence has the least information of the three, it does not even mention "in". Lots of assumptions here. Depends very much on the context.