"Best" depends on your context ....if you have a chemical autoclav you can use hydrogen and catalyst, you have a chance to reduce with Sodiumhydrid/Sodiumboronhydrid under atmospheric pressure or you can choose an enzym like Nitrilase to do this job. The best method depends on conditions like time, labequipment, chemical stability and, not to be forgotten, your budget .
Thanx frank... I have autoclav... I had one confusion can only meta catalyst as raney Ni can done the job or I have to add sodium borohydride or other as additive... and only sodium borohydride can reduce nitrile to amine.?