can i improve rc score in one month. i am getting around 10

tbh no, its too late but keep practicing and reading

yes you can but dont keep unrealistic expectations from 10 you can move to around 24 in cat if you go frenzy with quant prep just focus on geometry,arithmetic(most imp),alegbra.....atleast have a good grip on the previous years questions concept asked in cat from these topics

My score is a little inconsistent, varying in the range of 25 to 40, I would suggest to try different ways to attempt. Don't aim at attempting the entire section at one go. If you're comfortable with VA, don't miss out on any of those questions and attempt 2 RCs. With 8 questions of RCs, given you get 6 correct, you bag 16 marks. Moving on to VA, do not skip the TITA questions. Try and get 6 questions correct again, minimum, that's another (best case scenario you get only TITA wrong), you bag another 18. That's 34 in total. Try this, maybe it helps.