Trans slips on a slight incline

what causes this is it safe to drive to get it repaired

Describe exactly what you mean by “slips.”

Check your transmission fluid.

loss of power engine sounds strained. fluid level is good ,so is color of fluid

Well, now you have to describe “engine sounds strained.” If the transmission is slipping then the engine would be revving up really high without power going to the wheels - sort of like having it in neutral and trying to accelerate.

If the engine is bogging down or stumbling or something then you have an engine problem rather than a transmission problem.

What year is the Vitara, how many miles are on it, and what has it had in terms of transmission service over its lifetime?

2000 .just over 1oo,oo. the cars engine idles good runs with full power on a flat surface. I had to climb up a 20% incline in four wheel drive. Almost didnt make it . heared a sound coming from under driver side like a metal grating sound. seems like theres full power car just isnt moving . when i reached the top i disengaged four wheel. drove home on a flat ad and car ran fine with power but problem occures in and out of four wheel drive. the tran was inspected about two year ago. the car is shifting but lacks power

How many miles on your car and when was the last time the transmission fluid was replaced?

You just need to take it to a shop. Transmission slipping won’t come with a metal grating sound. Its basically impossible to tell, from your description, exactly what is happening. So I think you just need to have a good mechanic drive it.