Lack of time at a gun range was never an issue. The NSG operators are some of the best trained and most capable intervention operators in the world and an MP-5 in their hands is deadly, on an average training day they will go through over 200 rounds of ammo and they train for the "double tap" i.e. 2 rounds to the head and they are experts at this. There is one training procedure the NSG and all other Indian SOFs do and that is they have a target at 50m-70ms with their team-mate standing right next to it. The Shooter has to hit the target at that range with the margin for error being zero for obvious reasons.
Now obviously being a professional force the NSG have analysed what went wrong on 26/11 and taken steps to address these issues but very few of the issues were related to a lack of training or time at the gun range but issues to do with a lack of certain specialised or even basic equipment not to mention not having access to a a/c for a long period of time, a lack of blueprints etc etc
Almost every issues raised by 26/11 has been addressed to date, I can put my hand on my heart and say that.
Bro you've pointed it out yourself, this is an unanswerable question. Anyway the NSG can't be compared to the Military SOFs- Garuds, MARCOs or PARA (SF) as the NSG isn't a SOF but a specialist intervention/CT unit under civilian control (MHA).
As such the scope of the NSG's capabilities, training and mandate is very narrow and focused i.e. Hostage Rescue, CQB, CI etc whereas the true SOFs of India have a much broader training regime. Then to compare the respective SOFs (Garuds, MARCOs and PARA (SF) ) is an almost impossible task it really is because of the different nature of their roles and employment, differences in deployments and experience levels and their respective duties. It's like having a DELTA vs DEVGRU debate, you can't categorically say which is better.
Anywho, what is clear is that India has some of the finest SOFs and specialist intervention units around.