B12 deficiency - Neurobion inj or Nuroki

Sir, I am male 5fit 10 inch,  81 kg. Since last 5 years I am taking maintenance dosage injection of b12 once in a 3 months. My b12 level is 350 as per current report. Actually I was talking eldervit 12 but due to unavailability in my current city I consult MD Medicine who ask me to take Nurokind plus injection but after taking this since last 9 months 3 inj.. I am feeling lot of stomach gas discomfort. My all executive blood reports & USG abdomen is normal. I don't have any constipation or diarrhea problem. Kindly advise whether I can take neurobion inj or suggest good reputed company inj which can solve my stomach gas problem  and due to this I mentally also gets upset many times during day. I always remained worried due to gas & fart 6-8 times in a day. Or Kindly suggest good course of treatment to treat b12, anxiety & gas farting issue