There is one way to get free UC in PuBG for a very long time.

But, for that you need to spend Rs. 800 once.

So, This 800 bucks will give you 600+60 Ucs. total 660 UCs. You can buy Elite Royal pass for 600 UCs which will Unlock whole lot of cards, moves, apparels, coupons and UCs as well if you complete the weekly missions.

Please take a look at a screenshot below

as you can see in the above picture Elite royal pass will give you 30 UCs after every 5th RP. if you do all missions in 8 weeks (i.e., by the end of season) you will get your 600 UCs back which you can use in next season to buy Elite royal pass again. repeat same process in the next season as well to get your money back as well as some cool apparels and moves to show off in your squad.

Let me Confirm, as far as my knowledge is concerned, there is no other way than this to get free UCs.

Thanks