Index exceeds number of array elements in for loop

I'm trying to replace 0 with NaN if it is present at the 2nd or 6th element of a column vector. I also need to replace with NaN if there are 9 consecutive zeros, or two NaNs if there are 12 consecutive zeros. I then try to remove all the remaining 0s.

    RTa = cell2mat(Rxtcell);
   if RTa(2) == 0
        if RTa(6) == 0
            RTa(6) = NaN
        end
       RTa(2) = NaN;
    end
    
    for n = 1:length(RTa)
        X = RTa(n:n+8);
        X2 = RTa(n:n+12);
        Y = [0;0;0;0;0;0;0;0;0];
        Y2 = [0;0;0;0;0;0;0;0;0;0;0;0;0];
        if X==Y
            if X2==Y2
                RTa(n+1) = NaN
            end 
           RTa(n) = NaN
        end
    end
    RT1 = RTa(RTa~=0);
    
    

Gives the error

  Index exceeds the number of array elements (241).

Error in RTscript (line 11)
        X2 = RTa(n:n+12);
        
        

If I run script or copy-paste and run in workspace respectively.

Answer 1

[KALYAN ACHARJYA]

Error message providing sufficient reason for error

As you are trying to access RTa upto n+12, here n is max length(RTa).

Example:

A=[3,4,5,6]

Here length of A is 4, now if you wish to access the data upto 4+any value, is their any sense?