I see the slider has one handle and not 2? What does the url query string look like? Does it perhaps have something like 0+2000 in it? In which case, maybe you would need to use the Edit Query Arguments filter to make this 2000+2000. To see if this works, manually alter the url and hit GO in the browser to refresh/reload the page.

But the URL would need to look like this:

http://www.cybergiftindia.com/ottobanking/?_sfm_amount_of_the_loan_from=15000+15000&_sfm_duration_from=6+180&_sfm_age_min=18+40

I wonder if you could add some javascript to the page using the change or onchange of the from field to set the value of the to field to the same value?

I have been playing with the code and this will not work the way you have it. Instead of locking/hiding the upper value, can you lock/hide the lower value and not auto detect it but instead have it a 0? Then, instead of setting the match type to ‘Input within’, make it Input overlaps

As you have it, the visible slider is the From slider.

Well, whatever you did to lock/hide the To slider (the max value) would have to be moved over to the From (min) slider in coding.

As to the backend, open that field’s settings and find the Compare Mode select box, and change that from Input must be within the Post Meta range to Input overlaps any of the Post Meta range.