Hi rathika. First, I'm just a lay-person, OK, everything I know I learned here from paying attention to the advice others give and from reading. There are really experienced posters around, especially Leon, PMM and rjessome, and that is because they have been through this and rjessome is even an immigration consultant. So what I learn, I just share.
Your situation is complicated, so I would expect that they want to do an interview with your husband. As for when this will be, I don't know, only the IO can say that. Since they have not yet given you a date, it is possible it will not be before his medical expires. Here are some of the things that might concern an IO, from what I read in your post:
1) This is your third marriage and your third attempt to sponsor a spouse.
2) Your first marriage ended over suspected fraud and you withdrew your application to sponsor. Your second application was approved, and sometime thereafter you found him to be cheating and you got another divorce. Three years after the end of that marriage you became involved with someone else, and married him about a year later, whom you are now trying to sponsor. It would appear that all your marriages and sponsorships have happened in the last 10 years or so.
3) You said your husband is able to support you both in Sri Lanka, but you have opted instead to sponsor him to Canada.
4) You both practice different religions.
5) Very few of your relatives attended your wedding.
6) You are receiving disability support.
Basically, these concerns will fall under Section 4, or the "bad faith marriage" part of the Regulations and Section A39 of the Act, if they think he might be unable/unwilling to support himself in Canada.
Your husband should expect to be asked questions relating to everything you wrote about in your post. He should be familiar with:
- your previous marriages and why they ended.
- the reasons why you decided to marry a third time after two disastrous marriages and a suicide attempt.
- what about you he loves, so much so that he is willing to marry a twice-divorced woman with a history of suicide attempts.
- why he was willing to ignore his family's objections, or what reasons he gave them so that now they are willing to accept his marriage, or how he deals with being married to someone his family objects to.
- why you decided to sponsor him to Canada instead of going to live with him in Sri Lanka, since he earns a good living there.
- why so few of your relatives attended the marriage.
- how you reconcile being from two very different religions, and how you intend to bring up any children you have together.
- how you plan to support yourselves, what kind of work will he do if he comes to Canada.
- if your application is denied, what you plan to do (not just appealing, but what you will do if the appeal is denied).
That's as much as I can think of right now. This list is not exhaustive, and I suggest that you order your CAIPS/GCMS notes, perhaps the Immigration Officer has been specific in listing his concerns.
Your husband must be able to answer any questions similar to these, and must be able to do so clearly, without hesitation and with full honesty. He should never guess when asked about your feelings for each other and how they developed, your past or your future together as a couple.