If I _____ here, I shall come to you.
If I _____ here, I shall come to you.
Explanation
If I am here, I shall come to you.
This is a first conditional sentence, used to express a real or possible situation in the future.
The structure is:
If + present tense, shall/will + base verb
So:
"If I am here" (present tense)
"I shall come to you" (future action)