Your mortgage has several rates, one for each track. Fixed tracks (Kalatz, Katz) keep their rate for the whole term. Variable tracks follow an anchor: the Bank of Israel rate plus 1.5 points for Prime, or government bond yields for the tracks that reset every few years. Banks usually price each track as the anchor plus or minus a margin.
Rate and indexation are two separate costs. A Katz at a low rate is not automatically cheaper than a Kalatz at a higher one, because the Katz balance also grows with the Madad. The fair comparison is the "forecast total interest rate" that every approval in principle must show, which includes expected inflation and fees.
The pitfall is negotiating one headline number. A small cut on a fixed track you will keep for 25 years is usually worth more than the same cut on a Prime track, which you can refinance later without a capitalization fee. Today's market rates are on the rates page.
Example
On a ₪1,200,000 loan over 25 years, a 4% rate gives a monthly payment of about ₪6,334 and about ₪700,000 of interest. At 5% the payment is about ₪7,015 and the interest about ₪905,000: one extra point costs about ₪681 a month and about ₪204,000 over the loan.