If solipsism is to be believed, reality is simply the collection of your sensory perceptions. If this is true, then if you were in The Matrix, the "real world" wouldn't matter. Reality is just that set of perceptions for any given moment, it doesn't discriminate towards altered perceptions. You've simply altered your reality.

On a slightly less solipstic note, there can be an infinite amount of realities, because we each have a different experience. Even if we could be fed the same experience through altering our sesnsory perceptions, we would still bad at different points in space (although that maybe changed in the future by quantum state, but even then, we may label them 1 & 2, that small difference making them slightly different).