Best to create a small lookup table with the rates and 'from KM' limits. You can then use the LOOKUP function to retrieve the correct rate/allowance per KM. I've attached an example.

Sir

plz see the attachment and give me a best example

A screenshot isn't really helpful.  Especially as it doesn't include the column and row headers. Better to upload your file. When you do that, please don't forget to press "Start upload" before you submit your reply.

Sir

the distance and amount column is to be filled. If I enter a value in distance cell then the amount should automatically show the amount

OK. See attached. I included your form in the file I sent earlier. See if you can get it to work.

Sir

Your example that send already is multiplying and is not the actual amount that I want. For eg. when I type 2 in the distance cell then the amount column should be 10, And as per the sheet I've attached

I misunderstood and though the allowance would be per KM. If that's not the case, just remove the multiplication bit of the formula. That would then be:

=LOOKUP(E4,Table1[KM],Table1[Rate])  

Thank you sir but there is another problem is there. 0-2.5 is 10, 2.5-5 is 13, 5-7.5 is 15. so plz correct me sir

OK, My bad! I didn't read the 'upto' in your initial question.

See attached. And just understand, this work for upto the limit in the KM column. Not upto and including. If that's what you need, please change the limits in the lookup table.