Tarun it is highly unlikely that you will be able to find riding jackets and gloves on rent, though you can get warm jackets on rent from camping equipment stores like
Carabin. As for warm gloves, buy them from Manali, they would set you back by Rs. 150-300 for a decent pair.
Renting a saddle bag will be an issue as well as it is unlikely that you will come across a store which rents one.