You want it to be
I am not _____ (an adjective).
Because it is modifying a noun, in this case I. These are all valid:
I am not happy.
I am not tired.
I am not lazy.
However, it does not have to be an adjective that modifies a noun. You can have a participle modifying a noun. A participle is a verb in either past or present tense that acts like an adjective. So your sentence could be:
I am not _____ (a participle).
These are all valid sentences:
I am not tolerated. (Past participle)
I am not tolerating. (present participle)
I am not excited. (Past participle)
If you want to say that you do not tolerate something, you should use the word 'do' rather than 'am'. Do is about your actions (verbs) and am is about things that describe you. (Adjectives or participles).
So you could say:
I don't tolerate _____ (something).