My car sat for about 5 months in the yard. Clutch and transmission are new rebuilt. Went to move the car clutch went to the floor and stayed there. What can I do?

The clutch is not transferring power to the gearbox, which then is not turning, so that you can select gears without the clutch.Possibilities are
- clutch assembly has failed, possibly by the splined driven plate hub coming adrift
- clutch driven plate has become very worn and has lost contact
- slave cylinder has stuck through corrosion (assuming a hydraulic clutch) and is holding out the clutch independent of the pedal. This can be determined by watching it while someone depresses and raises the pedal.

I think it is unlikely the transmission input shaft has fractured.

Sound like you're going to need a whole new clutch assembly, but if the fluid level was dry you may have sucked air into the system which means that the clutch will have to be bled at the slave cylinder, just like you would brakes. The squealing sound is coming from the throw out bearing, usually when the do that it means that the bearing is frozen and cannot spin. Either way it looks like you'll be dropping the transmission to work on the clutch.

bad pressure plate or stuck throw out bearing.

no i thank there is air in the lines still try that

It sounds as if you have 2 problems here.

The fact that the clutch pedal went to the floor and stayed there suggest a fault in the master cylinder. It may be that you need to overhaul the master cylinder.

Overhaul kits are available at less cost than a clutch master cylinder:
0results for isuzu rodeo clutch master cylinder overhaul kit

The grinding noise ... A grinding noise would be caused by either the gear not engaging properly because of the defective clutch.

Or, if it is more of a squealing noise - that may be the clutch release bearing at fault.

Are you absolutely sure that your entire clutch unit - pressure plate, driven plate and release bearing aren't worn?
116results for isuzu rodeo clutch

if the clutch fluid is low you have a leak could be the clutch slave cylinder or the clutch master you should have it checked for a leaks

pull the boot back on the master and see if it is wet do the same with the slave

Jeep #1: Sounds like a shift linkage problem. Possibly synchro forks are sliding back and forth on shift rails and are out of adjustment. This is internal and cannot readily be fixed without trans removal as far as I know. Hydraulic clutch system is non-adjustable. A new clutch should last at least 70K so, unless it was installed improperly, it should be OK. Check hydraulics for leaks & bleed. Clutch should "catch" about two inches off floor (not too low or not too near top of travel)
Jeep#2: Has a synchro or other internal gear problem... Symptoms are similar but gringing and clicking noises indicate worn or broken internal components!
Good luck to both!

The first thing you want to check is the clutch master fluid, make sure there is enough in there. This sounds like there is air in the system.
You will have to bleed out the clutch slave cylinder. Get yourself a manual for the car and it will walk you through it.

try bleeding your clutch