Is it a good idea to get subglandular implant of 375cc high profile silicone with the asymmetry of my right breast? (Photo)

It is hard to appreciate the exact amount of asymmetry that you have based on your pictures because your arms are at different angles.  This tends to distort the breasts.  Volume-wise, you appear to have close to the same volume so I doubt that you would need different volume implants.  I think that you would be fine with placing the implants below the chest muscle.  I think this would give you the best result in the long run.  If one nipple/areola is noticeably lower than the other then this could be corrected with a peri-areolar (aka, donut) breast lift on the lower side.  Still, at the end of the day, a little bit of asymmetry is normal and natural looking.

Thank you for the question and pictures.  In my practice, I would likely offer you a sub muscular (dual plane) breast augmentation; the use of different size (sometimes even different profiles) breast implants would likely help improve breast symmetry. Ultimately, careful communication of your goals (in my practice I prefer the use of goal pictures and direct examination/communication in front of a full-length mirror) will be critical.
Generally speaking, the best online advice I can give to ladies who are considering breast augmentation surgery (regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully.  Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.
2. Have a full discussion and communication regarding your desired goals  with your plastic surgeon. This communication will be critical in determining  breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as  “natural” or "C or D cup” etc means different things to different people and therefore prove unhelpful.
 Also, as you know, cup size varies depending on him who makes the bra; therefore, discussing desired cup  size may also be inaccurate.  The use of computer imaging may be very helpful during the communication process.
3.  Once you feel you have communicated your goals clearly,  allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals.  Again, in my practice, this decision is usually made during surgery ( after the use of temporary intraoperative sizers).
I hope this, and the attached link (dedicated to breast augmentation surgery concerns), helps.