get record between two dates
The problem:


  date store in varchar MM/DD/YY


That is your problem. You are storing dates in character columns. Even worse, in a non-aligned format.

Solution:

Use a type that suits your data. You are storing dates, use the DATE type. 

Then you won't have to decide or worry about the internal format that dates are stored. You'll only have to provide date literals in a format that MySQL accepts (eg. ISO: YYYY-MM-DD). Your query would then work just fine:

SELECT * 
FROM new_item 
WHERE from_date &gt;= '2017-01-01'
  AND   to_date &lt;= '2018-02-25' ;