No . But he was warned by his uncle Malayavat and Kumbhakarna about Rama
Malyavat with two brothers fought against Vishnu. Sumali and Malayavat hid inside Patala fearing Vishnu after his brother got killed
- विष्णुं मन्यामहे रामं मानुषं देहमास्थितम् ।
- न हि मानुषमात्रोऽसौ राघवो दृढविक्रमः ॥
- “We consider Rāma to be Viṣṇu who has assumed a human body.
- For this Rāghava, firm in prowess, is not merely a human being.”
Ravan was blinded by pride and arrogance and couldn't recognised him.
Indradev refused to meet Rama in Aranyaka to conceal avatar identity
- ‘This Rama is coming here. You should nudge him towards his vow. Until then, he should not speak to me, or see me. When he is victorious and successful, I will soon show myself to him.
Footnotes say this :
This requires explanation. When soliciting a boon about who could kill him, Ravana forgot to mention humans and therefore, Ravana could only be killed by a human. Until this happened, if Indra spoke to Rama, Rama’s divine nature would have been revealed and he wouldn’t have been able to kill Ravana. This was to be avoided.
Pretty much no one considered Rama as human in contrast to Krishna who is more often underestimated by his enemies like Duryodhana.