Yes, RESILIENCY is a Scrabble word!

Letter values in Scrabble US: R 1, E 1, S 1, I 1, L 1, I 1, E 1, N 1, C 3, Y 4.

Is it a valid word?

RESILIENCY is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

an occurrence of rebounding or springing back
the physical property of a material that can return to its original shape or position after deformation that does not exceed its elastic limit