@ Triniflya
You can reference my post on page two (2) regarding conversion information [post number 22].
Brief summary: cost approximately $1500 TTD (approx. fees for TTCAA)
Timeline for completion will depend mostly on you. Mr. Nolton Peters was the go to guy for conversion process, but sadly he is not with us anymore, he was very knowledgeable and always fun to chat with.
Otherwise there is Pro ATS which is on BWIA Blvd who also holds a conversion course which a buddy of mine took. The cost was $1000 USD for their program. Other than that, he was happy with the program and the end result. Also, not on my previous post, if you have an ATPL you may only have to take the air law examination as a buddy of mine only needs to complete this exam for his conversion based on him having an ATPL ticket and the associated experience/hours.
Being a Local, Cal's last job posting for the ATR did not specify minimum hours. You require a Trinidad and Tobago CPL and Multi IFR (Group 1).