Idolatry in churches allowed? It is very frequent to see idols of Jesus or any biblical entities in  a Church , So is such idolatry allowed by  the bible,considering the following verses?


  "You must not make for yourself an idol of any kind or an image of anything in the heavens or on the earth or in the sea".
  Exodus 20:4


History tells us that:


  sometimes objects that God instructed to be made were turned into
  idols by the Israelites. The Book of Numbers contains a narrative in
  which God instructed Moses to make a bronze snake as part of
  addressing a plague of venomous snakes that had broken out among the
  Israelites as a punishment for sin. The bronze snake is mentioned
  again in 2 Kings 18; however, rather than remaining a memorial of
  God's providence, it became an idol that the people named and
  worshiped. Thus the bronze snake was destroyed in King Hezekiah's
  reforms.


More specifically in India I see Christians carry idols of Jesus and other biblical  entities with them kiss them and revere them too. Infact they allow the Hindus in the Church and let them perform worship in their way(Like putting incense sticks, offering flowers , foodstuff to the Idol of Jesus etc) as shown below a very common view in India. I studied in a Christian school for 10 years and i am yet to see Christians not doing these things.

I have seen the same on TV and in videos of people venerating the Idol of biblical entities.
You're operating under a misconception that these are idols. Most Christians don't worship these images, statues, etc. Instead, they are considered art, something that we  create because we love the subject, not the work of art.

Asking your question is like asking if looking at a painting of my wife means that I am allowed to cheat on her by devoting my affection to an image of her. I love her, not the painting of her. Christians love Jesus, not the statues of Him.

So, the answer id no, idolatry isn't allowed in Churches.  

Addressing the updates to the question, the things that people are "venerating" are likely "Sacrementals".


  Sacramentals are material objects, things or actions (sacramentalia) set apart or blessed by the Roman and Eastern Catholic
  Churches, the Eastern and Oriental Orthodox Churches, the Church of
  the East, the Anglican Churches, the Independent and Old Catholic
  Churches, and the Lutheran Churches to manifest the respect due to the
  sacraments, and so to excite good thoughts and to increase devotion,
  and through these movements of the heart to remit venial sin,
  according to the Council of Trent (Session XXII, 15).
  
  In Roman Catholicism, sacramentals such as Holy water, the crucifix or
  the Saint Benedict Medal are recommended as a means of protection
  against evil.


Again, the devotion is not to these things, but to the God they represent. There are, those that do worship them like idols, and many view the idea that these could protect us from evil as superstitious, the point remains that officially, these aren't idols. They aren't to be worshiped. They are reminders of the one we should be worshiping.