can i bi-amp my speakers with a rotel 6ch amp?

Sure you can. I now have a three channel amp, (and several monoblocks) but in general I have found several 2-channel units to be more convenient. Reasons include:

1. Multichannel amps can get darned big and heavy. Hard to locate, expensive to ship, and hard to move around.
2. If one channel fails, you loose six while repairs are made.

Yes, you can bi-amp using a multi-channel amp. I am currently using a 5-channel Rotel RMB-1075 to bi-amp my Revel F30 speakers. They sound good, but I'm actually researching the monoblock route, myself.

To bi-amp with a multi-channel amp, you'll need to get a Y-adaptor to take your single output from your pre-amp and split the signal into 2 different amplifier channels. You're going to spend more money on cables, as is probably obvious.

If you have not yet purchased your amp, I'd recommend auditioning different amps to make sure you get the most for your money. I think having better quality amps is better than bi-amping with lesser quality amps.

Good luck in your choice.

First let me confess, I am an adicted biamper...but...

What's all this talk about Y-adaptiors for bi-amping? What you need is an electronic (low level) crossover. If you drive both amps full range, most of the advantages of biamping are lost. Back when 25 watt amps were considered high powered, and IM distortion ran 1 percent or more, biamping made lots of sense. Today, if performance per dollar is your criteria, one better amp wins.