GTA 5 choppy gameplay

I think I know why. GTA5 is pretty resource intensive and a gtx1050 with a mobile CPU is going to be under heavy load. 90-95C temps are usual with that game, considering that this is a laptop.
The first time you start it, the game automatically uses a graphics setting that balances performance and visual fidelity. This one is not always a good one to use since it does not even do a proper benchmarking first. 
So I assume it's running on medium settings, unlocked fps and a specific option in gta5 dealing with population count. I have a 1050 too and for me, this setting was turned to high right from the start. Being the kind of game it is, the number of NPCs present on your screen at once has a big impact on performance since each character's behaviour is controlled separately by the computer. Try turning this one setting to low and see what happens. 

If the stuttering still happens, then make note of when it happens. For example, what's happening on screen at that time. Stutters are more likely when  things like sudden explosions and quick change of scenery(such as rapidly turning the camera) happen. Also, check the volumetric effects. I don't remember its impact in gta5 but generally that effect takes more resources. 
In the end, even if you turn all graphic settings to low and lock fps and get steady frame rates, your computer's going to run quite hot. Take it from me. Nothing you can do about it in gta5. I have an i7, 16GB memory and a 1050. I undervolted, repasted and use an elevated position to increase air flow. Still some games are going to make it hot. Sometimes it's the developers' fault for making badly optimised games. Other times, its no one's fault and you just have to accept that your hardware simply cannot do any better.

On default settings, most games run deceptively smooth for the prologue section. The real test comes later and then you'll see how it's actually going to be.

If you want, I can give you a few common methods for heat reduction but it won't help as much as you think it will.

Feel free to undervolt it. I don't think it voids warranty but I'm not 100% sure. Don't get your hopes up too much about the temperatures. It could drop by up to 10C maybe, once you've done all the home remedies. 
The stuttering, however can be fixed. I won't guarantee constant 60fps with those specs(even on low). But if you can ignore those occasional frame drops that happen once in a while, then you'll be able to play on smooth 60fps for, say 90% of the duration.

I should tell you that different games show different behaviour against undervolting and limiting clock. In my experience, most of the games will work as before, but a few will throw tantrums. Hitman(the newer ones) and witcher3, I remember specifically, used to freeze the computer frequently when using  particular offset values, even though other games and the system as a whole showed no signs of trouble. Also, this might be subjective, but on my computer, Horizon zero dawn gives slightly lower frame rates(from 25-30 range to 23-26) when disabling turbo boost, on some graphic settings.

Did the youtube video show the same laptop?

Oh. I am sorry for misleading you then. I played gta5 a long time ago and had forgotten quite a few things. I guess I was wrong to have put the average fps on 60. Truth be told I still don't remember the exact fps I got back then. I only know that I had 60 at least, on low.
As for why you are still getting only 40 after this, I am confused too. 

  So he had more RAM. That does help but your setup should be able to get 60fps at least. Did you do update your Nvidia drivers after buying the laptop?

Swaroop123 said:

Yeah bro I had done and I get 60fps but frame drops toooo and 

Then you finally managed to get 60fps good! How often do the frame drops happen?