As you know Rest API v1.1 doesn’t include specific request api for getting replies for particular post. There is no direct way to do this. The only solution is by using search api get all tweets which are posted after particular post and then check each one if the “in_reply_status_id” is equal with id of the particular post id. But there is another issue. Search api is returning only 100 post. So if the particular post is tweeted a week or a month ago and after that post is tweeted more than 100 replies for another post then there is no way to get replies for this post.
Is there any other solution to get last replies for a particular post?