I want to make a formula so that it can extract alphabets and numbers from a string containing both alphabets and numbers.

You will need to post some samples of the data. If there are are spaces, hyphens etc have you tried Text to Columns.

Here is the picture of the function

The post above suggesting you show some sample data, was actually asking for more than just one row as that tells us very little.

Would the numeric part always be 3 characters and in the 4th, 5th and 6th character position?

Also would the text always be 9 characters long.

If so, then you can easily use =LEFT() & =RIGHT() to get the alpha and =MID() to get the numeric.