for those holding every 1000 share MAS will entitle to buy 4000 shares (MAS) with RM0.23 per share....
but then there is a capital reduction on par value from 1.00 to 0.10.... i am not sure whether will affected the quantity holding ... anyone can clarify on the this....

As per example of cherroy:
Even if the price after the ex-right issues date is above 0.34, EPS is still going to be diluted.
So, not a good idea to subscribe?

Share price in the market will be adjusted on the ex-date of the right issue accordingly to the portion of right issue.

For eg.
if closing price of prior before ex-right share date is 0.76, and it is 1: 4 right issue at 0.23, the next trading day, the share opening indicated price will be

[(0.76 x 1) + (0.23 x 4)] / 5
= 0.336.

So the opening price on the ex-right shares date will be 0.34.

If the share price doesn't go up beyond 0.34, one is not making any money from subcription of the right issue.

Basically, the share price won't stay at 0.76 on the ex-date on right issue, the share price will be adjusted for the right issue.

Since the right is renounceable, means one can actually sell the right/form of the right share (without need to fork out money or don't want to buy the right issue at 0.23 ),

The right (probably with the name/code MAS-OR) will be traded (for about 2 week), at the difference between 0.23 and share price on the particular day.
So if the adjusted share price is 0.34, the renounceable right may be traded at around 0.07~0.08 (as the renounceable right worth = share price after adjusted - 0.23)

With 11 billion plus in Mas shares, how much profit must Mas make to have any impact on the EPS?

To contribute 1 sen, Mas needs at least RM100 million in profit.

Only after you subscribe the right.

MAS-OR allow you to buy MAS right share at 0.23.

But it takes sometime (weeks) for the right issue to be completed. So there is "time risk" in between.
As we do not know what the MAS price will be when the right issue completed time.
It may higher or lower than 0.37.