When a positively charged body is brought near an uncharged metal rod, the part of the rod near the charged body acquires a negative charge, and the far side a positive charge. Can you say why this happens? Remember that in a body negative charge are mobile whereas positive charge are fixed.
When a positively charged body is brought near an uncharged metal rod, then the positive charge of the body will attract the negative charge in the metal rod, as like charges attract each other and unlike charges repel each other. Since the electrons are the negatively charged particles, therefore the electrons will move towards the end which is closer to the positively charged body. The other end of the rod becomes deficient in electrons and therefore acquires a positive charge.