got/get

  1. I just had my interview. I don’t know if I got it or not.
    1a. I just had my interview. I don’t know if I get it or not.
  2. I just took the exam. I don’t know if I passed or not.
    2a. I just took the exam. I don’t know if I pass or not.
  3. If I will do this, I will be wrong.
    3a. If I do this, I will be wrong.
    3b. If I do this, I am wrong.
    3c. If I do this, I was wrong.
    Please correct and guide me with correct tenses.
    Thanks.

I think you are a user of this forum with the largest number of posts/queries. Though it is appreciable, I cannot but wonder why you sometimes raise very simple (I don’t call them silly) questions like If I will do this, I will be wrong and If I do this, I was wrong.

Anglophile,
To make sure myself that I am not wrong with use of tenses, I am putting the questions.
Please don’t get annoyed if I ask some fundamental grammar questions.
Please guide.
I am looking forward to you all to help me.
Thanks.

Incorrect: 1a 2a 3 3c
3b is possible, but in most circumstances (contexts) it would be the wrong choice compared to 3a.
Posting isolated sentences will never clarify which tense should be used in particular circumstances. The best it can do is to identify which are definitely never going to be right.

Beeesneees,
Could you please explain the grammar involved how “I just had my interview. I don’t know if I get it or not.” is wrong?
Thanks.

You used the present tense ‘get’ instead of the future tense ‘will get’:
I don’t know if I will get it.

Never, Madam, never. Don’t mistake me.

By the way, please check whether it is ‘to get/get through the interview’.

I just had my interview. I don’t know if I got it or not.

‘It’ refers to the job/position you were interviewed for, not the interview.