you need to be medically fit before joining ICG, you will not be granted leave for LASIK as it is considered a cosmetic surgery
after lasik it takes a minimum of 3 months for your eyes to get back to the required standards. Can take upto 6 months also.
All depends on your eyes and the type of LASIK performed.
I had undergone LASIK by a Dr in Juhu,Mumbai who was aware about the standards required for LASIK for F16 pilots at USAF and not DGCA/IAF.
All his reports after 3 months were approved by IAM and DGCA and had got FIT in class 1 renewal. Although IAM did their own tests also to verify reports.
Hope this helps