Yes, you surely can avail the NCB if you change your insurance provider at the time of renewing the policy. All you would need to do is producing a proof of the earned NCB from your current insurance provider. You can produce the original copy of your expiring policy and a certification that you haven’t filed any claim for the (expiring) insurance plan. A renewal notice or a letter stating that you’re entitled to the NCB from your previous insurance provider can be a proof for this.
In several countries insurance companies offer direct repair programs (DRP) so that their customers have easy access to a recommended car body repair shop. Some also offer one-stop shopping where a damaged car can get dropped off and an adjuster handles the claim, the car is fixed and often a replacement rental car is provided. When repairing the vehicle the car body repair shop is obliged to follow the instructions regarding the choice of original equipment manufacturer (OEM), original equipment supplier parts (OES), Matching Quality spare parts (MQ) and generic replacement parts. Both DRPs and non OEM parts help to keep costs down and keep insurance prices competitive. AIRC (International Car body repair Association) General Secretary Karel Bukholczer made clear that DRP's have had big impact on car body repair shops.