my 2000 eclipse won't go into reverse

the other day when driving the car tryed to put it into reverse and it would go but then it would kick it out of gear and make this grinding noise the car will go into reverse for a minute but then it will kick it out and make the grinding noise what could it be

Could be your linkage underneath the hood. Have someone sit in the driver's seat with the brakes on and manually move the lever to shift it into reverse. If it does fully click in, watch it to see if it knocks itself back out. If it does, you got some internal tranny problems.