How can we receive a global ipv6 subnet?
You can either register as a LIR (ISP), or you can apply for a PI (provider independent) assignment of IPv6 space.
The RIPE (European) policy is here, but the principal technical requirement is that you demonstrate that it is multihomed, ie that you have more than one independent route to the internet. You can get a /48 this way (you can apply for more, but "Organisations requesting a larger assignment (shorter prefix) must provide documentation justifying the need for additional subnets").
If you apply direct to RIPE, you're a Direct Assignment user; you pay €2000 to create the account and an annual maintenance fee of €1300. You'll need to have an AS number already
Alternatively, you can apply for PI sponsored by a LIR. The LIR pays €50 pa to RIPE for the independent resource assignment (on top of their membership). They can charge you whatever they like, but the Direct Assignment prices put a cap on the pricing.
You can also get routeable PA (provider assigned) space, which is an allocation from a LIR. If you get a big enough block (/48 or bigger), that can be routeable (ie appear in BGP) as well.
Regardless, if you want real routeable IPv6, then you need at least two independent routes to the internet (multihomed), which means two permanent lines to two different ISPs, or one such and a tunnel-over-IPv4 for the other. You will also need to run your own router that will talk BGP to both your upstreams and determine routes for all your outbound traffic.
We have a /24 IPv4 PI allocation and are in the process of getting a /48 PI IPv6 allocation, both sponsored by our ISPs (in their capacity as LIRs). We have two physical lines to two different ISPs, and routers running BGP talking to the ISPs. There's several thousand £ of infrastructure there. But we can change ISP remarkably quickly without renumbering anything, and all our traffic fails over between our ISPs.
Update: ARIN policy also makes an initial allocation of a /48 and charges $1250 for an initial allocation and $100 pa for maintenance - that's in addition to the $500 for an AS number and $100 pa maintenance for an unlimited number of ASNs.
APNIC policy is also for a /48, and charges AUD 4,175 for initial allocation / account setup and AUD 675 pa for renewal.
You can look up LACNIC or AfriNIC yourself if they apply to you, I'm afraid I don't have time (but will bring comments up into the answer with credit).
You can obtain a tunnel through any of the brokers - Hurricane Electric has a list of geographically diverse endpoints. Performance is better if you're close to an endpoint, however it isn't absolutely necessary to be near your endpoint.
Alternatively you can become an ISP -- you will need to apply for address space from a local registrar (and you'll need at least a few v4 addresses too - so this is expensive). You will then need to make transit arrangements with someone to carry your IPv6 traffic (this is VERY expensive), and get connectivity run to your location (this is HIDEOUSLY expensive).
(Nickel's worth of free advice: Stick with a tunnel broker.)
I might be reading too much into your question, but you said you wanted a routed IPv6 subnet. The only way your are going to get a route-able subnet without your ISP being involved is through a broker. Period.
If you don't need a routed address you can get a unique-local-address. This is the IPv6 equivalent of the 10.x.x.x address space. http://en.wikipedia.org/wiki/Unique_Local_Address
Or, if you have a large global network you can get a global address space. Big organizations like Google or IBM get these because their operations literally span the globe. But honestly if you were a global operation you would have IPv6 connectivity available to you.
As voretaq7 said ... "Stick with a tunnel broker."