RIPE and DNS delegations for provider independent addresses

In case "companyA" has /24 provider independent network allocated by RIPE, which has RIPE NCC as a first maintainer and "companyA" maintainer object as a second maintainer, then is "companyA" able to delegate reverse DNS queries to the DNS server it prefers? Or should "companyA" contact RIPE NCC in order to get reverse delegation(http://www.ripe.net/data-tools/dns/reverse-dns) done? In addition, if I know the provider independent IP address, then is it possible to view the delegated DNS server using the whois.ripe.net database? So far I have used "dig +trace -x I.I.P.P" and followed the chain of delegations. regards, martin