I am declared medically unfit for mild cubitus valgus in my NDA medicals. Suggest me exercises to decrease it by a degree or so.

Question

There are many functional factors and perpetuating conditions that can produce and exacerbate a condition of Cubitus Valgus
there may be a deformity of the elbow joint that needs to be corrected surgically; only your examining physician will have a clue. If there is a joint or connective tissue lesion or deformity, it will probably need to be surgically repaired.
Also, there are also other neuromyofascial considerations that may be affecting your condition, such as active trigger points in lateral triceps, brachioradialis, and pronator teres, that can produce the posture and functional weakness of cubitus valgus:
If these muscles have even a latent (non-painful, but ROM limiting) trigger point, they can be easily released non-surgically, with function and comfort restored through rehabilitation protocol for these muscles.
You ask about possible lifestyle changes to help with your condition, but this is exactly the sort of question that I (or anyone online) can't answer: it needs a full history and in-person examination. Per your question, I don't know your occupation, past medical history, medications, hobbies, and about a hundred other details.

Vaibhev Mittal · Accepted Answer

There are many functional factors and perpetuating conditions that can produce and exacerbate a condition of Cubitus Valgus
there may be a deformity of the elbow joint that needs to be corrected surgically; only your examining physician will have a clue. If there is a joint or connective tissue lesion or deformity, it will probably need to be surgically repaired.
Also, there are also other neuromyofascial considerations that may be affecting your condition, such as active trigger points in lateral triceps, brachioradialis, and pronator teres, that can produce the posture and functional weakness of cubitus valgus:
If these muscles have even a latent (non-painful, but ROM limiting) trigger point, they can be easily released non-surgically, with function and comfort restored through rehabilitation protocol for these muscles.
You ask about possible lifestyle changes to help with your condition, but this is exactly the sort of question that I (or anyone online) can't answer: it needs a full history and in-person examination. Per your question, I don't know your occupation, past medical history, medications, hobbies, and about a hundred other details.