You can only request Provider Independent (PI) IPv6 assignments and Autonomous System Numbers through a Sponsoring LIR (a RIPE NCC member).
Best common practice states that Provider Aggregatable (PA) address space is the only way to scale the Internet and minimise the number of routes.
As an End User, you can request independent Internet number resources - IPv6 Provider Independent (PI) address space, Autonomous System (AS) Numbers, an IPv4 IXP assignment or an IPv6 IXP assignment - through a sponsoring LIR (a RIPE NCC member).
To do this, you must contact an LIR and request an assignment through them. The sponsoring LIR will then request resources from the RIPE NCC on your behalf. To obtain these resources, the End User needs to have a contractual relationship with a sponsoring LIR.
In 2008, the RIPE community accepted the policy "Contractual Requirements for Provider Independent Resource Holders in the RIPE NCC Service Region".
Please see Requirements: End User Assignment Agreement for more details.