Question

if he tried again,he___(add a tag question)

Answer 1

$= = = = >$

he tried again, didn't he?

Answer 2

if he tried again,he___(add a tag question)

Answer

If he tried again, he____? I think this question doesn't make any sense. For me your question should be like as shown as below:

He tried it again, ______?

Now, you can see it is proper tag question.

He tried it again, didn't he?

Done.