can someone please tell me how to do it and what is TTT and buffer

Now to do the rolling death cradle, you must first do the chain throw starter, Hyper Arm Extension (f,N,d,d/f+1+4), follow up with Chicken Wing Face Lock (2,1,1+2+3), then your Rolling Death Cradle (1+3,3+4,2+4,1+2,1+2+3). The RDC deals 79 damage, not 75 like the move list says. Good luck; you're going to need it 'cause of the very hard command for RDC.

Between you and me, I never bother with King's (or for that matter, most other characters') multi-parts 'cause most are easily escaped anyways. Not to mention the tendency of multipart throws containing something like (i.e. 1+3, 2+4, 1+2+4, etc.) which makes it even more difficult to see success. Now, this is just me; I only do Anna's multi-parts; not just because she's my favorite character, mind you, but she has manageable commands for her multi-parts worth practicing.

If I were you, if you have TTT, T4, T5, and T6 (or combination thereof), go to practice mode, pull up his command list, and you should watch a small demonstration of what needs to be done and when. Hope this helps.

Ive mashed during the hard part of RDC and still did it

(after the chicken wing)