Hi there,
I want to move a domain to Gandi and create a fresh box for it. The Domain is “.de”, and I want to ask, if Gandi’s Secondary DNS (ns6.gandi.net) is supporting DNSSEC and the TLSA Records.
Thank you for your answers 
I think DNSSEC is okay, not sure about TLSA.
Gandi Wiki regarding DNSSEC
Our secondary DNS, ns6.gandi.net, poses no problem, however, so you can set up your own primary and allow ns6 to obtain the zone file as usual.
Gandi also otherwise mentions (which you probably knew) their secondary can be helpful for domains such as .de requiring a secondary.
Our secondary nameserver can be useful if you only have one nameserver, but need another; for example, in the case of .de domains in which you need to have at least 2 name servers in a different physical location.