Yes receive address is mine. (its my exchange account wallet address). if i do RBF or CPFP, which private key should i get Exodus wallet or blockchain.com wallet ?.
You can't do RBF as your transaction doesn't signal that. CPFP is not possible since you do not directly own the private key to that address.
is it 100% success method?.
If transaction not confirm what will happened?. Will it return back to my wallet?.
The transaction accelerators (at least the trusted ones which are linked to a pool) will include your transaction into the blocks that they are mining. This means that your transaction would potentially be confirmed if they manage to mine a valid block soon. There is no time guarantee to it AFAIK and the pricing can be upwards of $50.