i make a gif and i want from 115kb resize to 25kb??
how can i do it?

resize the images, loose colour (256 to less), or use static background and only some small moving objects (that helped me ones).

Physical size is the main factor to reduce K. But lossy and dither factors can help. Then there is several color amount choices from 256 all the way down to 2.
Also remember if physical size is important like here, where it can't be smaller then 500wx350h, then have a white background at that size and reduce the actual animated frames down to smaller on top of that. Hope this helps.

Save for Web > Optimize to File Size