Is that any possibility to change or reduce the quantity of sand as fine aggregate in concrete?

Sure there are many ways, an all go through practical concrete trial batch.

An appropriate, desired mix can be produced with less quantum of fine aggregates with better grading of course aggregates.

That will give you cost saving on cement consumption as well.

Sand is only a fine material in the concrete, but has an effect on the strength. You want to reduce it because of costs? you can reduce the quantity by using cheaper fine material. But my advice : always test it!

There no way Since in every concrete mixtures has its own disgn mix if you will reduce the sand it means the design strength of concrete has been change.