hey guys thanks for the suggestions and in this case i am not trying to change my engine oil. actually its been like a 3 weeks i haven't drove my car and somehow i went to check the oil level and its was in low.  and i have drove 800 miles since i have change the oil, so i thought its not safe to drive a car with low engine oil so i thought to add some engine oil and i was confuse what kind of oil goes in engine. 
anyway guys i like the good suggestions
ani thanks chandrika, for letting me know abt the safety.