If I couldn't get out of it could she come with me?
If I can't get out of it can she come with me?
Which sentence is correct as I want to use for if condition talking about future?
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For the "if" clause, use "can". Here the meaning of "can" is "be able" and you want to use the non-past form to talk about the future.
For the second part there is a difference in meaning. We can use "can" to mean "is she able (or permitted) to come with me" But "could" is also used to mean "is it possible that..." Using "could" is more 'tentative', so it might be useful if you are asking for a favour. So for the second part both "can" and "could" may be used, with very similar meanings.
If I can't get out, could she come with me (is it, perhaps, possible for her to come with me...please)
If I can't get out, can she come with me. (is she able and permitted to come with me)