The given string is,

Step I: The position of each vowel of the string is exchanged with that of the element which immediately precedes that vowel.
Here, E, A and I are the vowels.
We get,

Step II: The first six elements from the left end of the string are placed after the last element of the string in the reverse order.
Here, J, Q, 1, %, Y and E are the first six elements from the left end of the string.
We get,

Step III: Each number which is immediately preceded by a number is placed at the left end of the string in the descending order.
Here, 9 and 8 are such numbers.
We get,

Step IV: Each symbol which is immediately preceded and immediately followed by a symbol is placed immediately after the first prime number from the left end of the string such that the first such symbol from the left end is placed first and the second one is placed immediately after it and so on.
Here, '!' is such symbol and '7' is the first prime number from the left end.
We get,

The final output is,

'N' is seventh from the right end.
