WASHINGTON--The congresssional Iran-Contra investigating committees approved the final draft of their report on the affair yesterday as House Republicans unanimously voted against it and voiced complaints that it is laced with "unsupported conclusions and innuendoes."

The Senate investigating panel was reported to have voted to approve release of the document 9-2, with two of the panel's five Republicans voting no.

Lance Morgan, spokesman for the Senate committee, said. the report is expected to run 450 to 500 pages and to be released November 17.

Dissenting Republicans on the two committees are expected to issue their own minority report at the same time.

Rep. James Courter, (R-N.J.), said the majority also rejected three specific Republican recommendations he said were intended to prevent leaks of classified information.

According to Courter, these included combining the existing Senate and House intelligence committees into a single joint intelligence committee and "tightening up on non-disclosure requirements."

Courter said there were two major reasons House Republicans voted against the majority report:

"The way it's written appears to bend over backwards to assign blame to the Reagan-Administration," he said. "And it contains innuendoes unsupported by the documents we have."

He also complained that at least, by implication, the report accuses the administration of a "cover up" after initial disclosures that money from secret arms sales to Iran was slated for diversion to Nicaragua's Contra rebels.

Courter said the report also implies that President Reagan "had knowledge" of the diversion.

"We take exception to some of their conclusions and some of their recommendations," Courter said, declining to elaborate.

The two committees, acting jointly, launched their investigation 11 months ago. The final report has been through many drafts and has been subject to intensive scrutiny and debate inside the two committees.