Gst on employee benifit expenses

Suppose company allow traveling expenses to employee(business purpose)
Case 1: whether company can avail ITC on gst paid on IRCTC tickets.
Case2: company send its employees to tour for business purpose than for Hotel bill expenses and other on whixh GST charged than what procedure to be follow to avail ITC on this.
Case 3: If any tour expenses occurred from URD than RCM applicable or not, If applicable than ITC available or not.
Case4 If company rapay these charges to employee itself than ITC available or not, RCm applicable or not.