the problem was coming when I'm trying to opposite the movement making the text moving from left to right.
When i'm setting animate "position" to move from left to right, the text will start from first character, meanwhile I was trying to make smooth sliding effect by starting from last character to first character. (I hope I don't make anyone confuse).
So, is there anyway I could do to make sliding text effect from left to right starting from last character to first character?
Twirl down the range selector of your text animator and keyframe End to 100%. Make sure Start is set to 0%. Move down your timeline a bit and keyframe End to 0%. That should bring the text in, one letter at a time starting from the last letter and ending on the first. Whether it comes in from the left or the right depends on where you set the animators position.