what you are talking about as good as upgraded mirage 2000. I repeat Tejas is nowhere as mirage 2000. Tejas mk1a will outmatch mirage 2000 in all areas except payload. Astra on Tejas might give it bvr advantage but BVR battle is tricky . And at best Tejas can only carry 2 astra to mirage 6 mica + 2 drop tanks. In 1vs 1 mirage 2000 will always have upper hand even against Tejas armed with astra missile, simply because mirage can dodge 2 astra missile fired from 50+km distance and turn cold . After 2 missile gone, it would be dogfight in which m2k will beat Tejas quite easily. Don't underestimate mica missile it was primary weapon of rafale until meteor was operational means (2018).
Astra outranges mica significantly. On top of that mk1a will get derby ER . NEZ of derby ER is more than twice of that of mica. Mirage in bvr is at severe disadvantage against lca mk1a.
Not only mk1a has missile with more NEZ it also has much lesser rcs. On top of that it has aesa which is jam proof compared to pesa in mirage which can be jammed .
Now mirages can still dodge bvr missile with it's potent ew but mk1a is ew si equally matched if not better. So it's just as likely that lca can dodge mica too.
Then again lca won't go against any mirage 2000 anywhere . It's opponents are chinese and porky jets.
Also lca can carry 2 ccm + 4 astra or 4 drrby ER + centreline drop tank.
Or alternatively lca can carry
2 ccm + 3 derbyEr or 3 Astra + 2 drop tanks ( 1 centreline) .
So mirage in 2 drop tank profile can carry only 1 or at most 2 missile more .
And by the time lca has fired 3 astra / derby ER . It will either be already in dogfight with mirage or it would have turned back whatever tactics it develops against f16 or mirage type jets.
But if I were in a mirage 2000 with pesa radar and mica missile (60-70km range) I wouldn't like to face an mk1a with elta 2052:: much lesser rcs and derby ER (160km ) or Astra (110km) . The odds are just not in my favor there.