Changing the Academics Board from State Board to CBSE

As far as I am concerned, it may not make much difference from one board to the other. It all depends on the individual and concentration on studies and how focused the student is. But many parents feel that CBSC is a better option than the state board.
Your elder daughter is in 9th class and your second daughter is in 5th class. It is not wise to change the board of your elder daughter now. You should continue her in her present syllabus. If you change her now, she may lose some time getting adjusted to the new syllabus. So you allow her to continue in State syllabus and after 10th class admit her in a good corporate college which will give coaching for admission to B.Tech or MBBS course simultaneously while coaching for intermediate. Definitely, she can do well. Many of the AP students who are doing intermediate in a good corporate college are coming out successfully even in the IITJEE entrance test and we see many from Andhra in the list of top rank students.
If you feel like it, you can admit your second daughter to CBSE. That will not have much implication for her studies as still, she has to read for five years to complete her SSC. Definitely, CBSE is tough when compared to State Syllabus. Scoring higher percentages is easy in the state syllabus than in CBSE. Students interested in going abroad for their higher studies can think of CBSE. Otherwise, both the syllabus will be the same for their further studies in India.

If you are interested to change CBSE pattern from the existing State Board one for both of your daughters, it is not likely to impact them in any way. The course structure of CBSE has been made taking care of their mental growth in the systemic way from one class to other one. It constitutes a panel of academics who are putting their relentless service to promote excellent academic standards for the pupils.
However you need to ensure that the schools where they are likely to receive education is known for their quality education with the dedication of the teachers. Both the pattern of studies followed by the right guidance of the teachers would create confidence among the pupils to receive right amount of course structure so that that would be far more competitive in their studies and it would prove ultimately that they are more competent and efficient in the CBSC pattern which might not have been achievable in the State Board Pattern.
Allow your kids to be tuned with the CBSC pattern for a couple of years so that they could accrue the real benefits.

Nowadays all the education boards are slowly aligning themselves towards the same syllabus but the only difference is the way of teaching and the environment of the schools falling under different boards. Every board has its own culture and reputation.
In my view if the students are laborious and intelligent then they can perform well in studies and make a good career. Why I am telling this is because if we see the performance of the candidates in top examinations like IAS there is no pattern that more CBSE studied people got through or more state board studied got through.
If your daughters are very good in studies then shifting would not be of much significance but if you are having some feeling that the environment in state board schools is not as good as that of the CBSE then you can take a decision of that sort.
There is a common belief in people that CBSE syllabus is better for appearing in competitions and students get an edge if they are from CBSE schools. I do not agree with that because ultimately what counts is the hard work of the student and only sustained efforts help a person in achieving success irrespective of which type of school he or she belongs to.

I think all boards have almost a similar pattern. There is not much difference between the state board and the CBSE board. Nowadays, most parents prefer the CBSE board because they think that all competitive exam syllabus is based on CBSE. But, it is not like that. It all depends on the student. If students are studious then/ her performance will be good in every aspect. I have seen many state board toppers getting good ranks in IIT- JEE and NEET. As per my suggestion, it would not be a prudent decision to change the board of your elder daughter because now she is in 9th class. If you change her board then she may take time in adjusting there. And it would be a disturbance in her studies. In the case of a younger daughter, you may take this decision because she is in the lower class. School and board don't matter in making a career. I have read many examples where students who come from rural backgrounds got good ranks in the IAS examination. Hard work with dedication has an important role in making a successful career.

The pattern of lessons and mode of teaching, examination etc., will definitely vary from state board and cbsc. If you are switching to cbsc from state board the following personal details are to be observed.
a. The capacity of children in understanding and coping up with change in pattern and subjects
b. The distance between house and present school as well the proposed cbsc school should be observed
c. The capacity of parents to meet out the fees and amenities should be seen