How to give one values to multiple keyframes in graph editor in blender

Question

I want to select multiple keyframes and give then one value at the same time which we can do it in maya but am struggling to do that in blender.

Answer 1

Without knowing which kind of keyframes and if by multiple you mean multiple in a single channel, or multiple channels or even multiple objects I can only give you a general answer:

Like most value fields in Blender, the values of multiple keyframes on various channels can be changed by holding Alt while clicking into the field before entering the value.

Before:

After:

If you disable the Only Show Selected option (the arrow symbol to the right of the menu bar), this works even with selecting multiple keyframes on different objects at the same time and even with mixed kinds of values, like Translation and Scale in the following example (only Rotation is a bit tricky, because Blender is then converting degrees in radians and vice versa):

Before:

After:

More information on the Alt method and how you change multiple values at once you can find in my answer here: Video Editing: apply transformation to mupliple images