DSSSB

From the Shiksha website, you can download the question papers of the DSSSB TGT for last year. It also hosts a large repository of learning material that includes the PDF of the previous question papers of the TGT, PGT, and PRT post, which you can browse through to familiarize with the exam pattern and the kind of questions asked in the examination. Regular practice with these papers will significantly improve your preparation and give you a lot of confidence at the time of the exam. Moreover, you might also look forward to participating in online forums or study groups where you can discuss strategies and share resources with fellow aspirants. Proper use of these materials will help in achieving a better understanding of the requirements of the exam and enhances the chances of success.

Eligibility for applying for TGT (Trained Graduate Teacher) Natural Science with DSSSB may differ according to individual eligibility criteria generally listed in the official notification for the concerned position. For TGT Natural Science position, the usual requirement is :-

Educational Qualifications :- A Bachelor's degree in the relevant field, such as B.Sc. with any Biology, Physics, or Chemistry specialization, combined with Bachelor of Education (B.Ed.).
Age Limit: Usually 32 years, but depending on governmental condition could oscillate.
For your case:

It mostly disqualifies B.Sc. Nursing that has no direct ties to such traditional sciences as Physics or Chemistry.
It might fulfill what is being sought by an B.Ed. in Physical because it does take care of specialisation in either Physics or Chemistry as part of the requirement, but that is subject to which notification is out from DSSSB.
It is important to note that the latest DSSSB eligibility criteria would need to be checked specifically, as they could differ from one year to another and even from one recruitment notification to the other. Such detailed information on qualifications for TGT Natural would have been availed at the DSSSB official website or the latest job announcement with respect to positions such as TGT Natural Science.

Probably, on the basis of eligibility, you can apply for the DSSSB (Delhi Subordinate Services Selection Board) exam in Chemistry for PGT (Post Graduate Teacher).

Regarding the PGT Chemistry position, the general eligibility criteria are:
A person's hold on at least a master's degree (MSc) in Chemistry or a subject related to it; you have done it in Organic Chemistry.
A person must also have a B.Ed. or a Bachelor's degree in Education, that you are pursuing. A B.Ed. is usually completed before the application; however, as you are completing it, try to check whether you will be eligible to apply during the final steps of your B.Ed. or after it.