Your information is wrong that we don't have male nurses in India. Men are admitted to nursing courses and there are many males working as nurses in India. However, proportion of females is higher than that of males. This may be because:
a) There may be fewer seats for males;
b) Fewer men may be applying for these courses;
c) Fewer jobs may exist for male nurses compared to females;
d) Male nurses employed in hospitals might be mainly assigned administrative rather than patient-care duties.
You may write to Nursing Council of India and the Trained Nurses Association of India for more information.
Male patients certainly have a right to demand male nurses to attend on them and if this demand is not met, they have a right to seek treatment at another hospital where this demand is met. You may seek information from the Nursing Council under RTI Act [Right to Information Act]. You may also get information from government hospitals under this Act. Nurses Association and private hospitals are not covered by the Act. You may also get information from the Health Ministry directly under the Act. When a male patient is being examined, he is within his rights to request the doctor to send out the females.
It is standard medical teaching that injections in the outer upper quadrant of a buttock are safe because there is no nerve there that may be injured, causing paralysis. There is higher risk of causing injury to a nerve [radial nerve] if injection is given at the back of upper arm [triceps area]. Injection in arm can be given safely at the upper part, [deltoid area], but is quite painful. It is less painful at buttock. There is more muscle mass there, so absorption of the drug is quicker. Some oil-based injections have to be given at a deeper site, which is not possible at shoulder. In the present era of litigation against doctors and hospitals, staff would be well advised to adopt safe policies, so as to avoid litigation later.