Unless that rumour holds any weight, I don't see any of them getting signed. Even Tamim, who is the likeliest, doesn't have a strong case. His form is down, he has a less than ordinary T20 record and failed in the County T20 competition.
I actually think he would do pretty well if he did get the opportunity but there will be a lot of completion for places as the former Kochi players will be up for auction. Players like Jayawardene, Brendon McCullum, Parthiv Patel, Ravindra Jadeja, Murali, RP Singh, Vinay Kumar, Sreesanth are all going to in demand.
I think it will be easier in the future for Bangladeshi players to get a IPL (or any other overseas T20 competition) place as they will have the opportunity to showcase their talents in the BPL and maybe even the Champions league.