Are Devas like indra god?
They are Devas, but they are not the supreme Brahman. They are Jivatmas who have done lots of good deeds, so they are born as deities such as Indra, Rudra, Brahma, Agni, etc.
So my question is how can a Gods do this?
Because deities like Rudra, Brahma, Indra, Agni, etc. are not the supreme Brahman (God); they are impure and still bound by karma and the three gunas.
Narayana (Vishnu) on the other hand is the supreme Brahman and his acts are pure; hence, he does not rape or murder.
Rudra is a created deity still bound by sin (papa), as shown in this Shatapata Brahmana verse:
“Pragâpati said to him [Rudra], 'My boy, why do you cry, when you are born out of labor and trouble?' He said, 'Nay, but I am not freed from sin; I have no name given me: give me a name!' Hence one should give a name to the boy that is born, for thereby one frees him from evil;--even a second, even a third (name), for thereby one frees him from evil time after time” - (Satapatah Brahmana 6:1:3:9)
The medieval Sri Vaishnava scholar Pillai Lokacharya has elaborated on the faults of these mortal Devas, and have shown that they are not adequate protectors:
And more, they [the Devas] are sometimes known to be vanquished by such mighty Asuras as Hiranya and Ravana, and compelled to do for them all sorts of menial services.
But what about Indra, Brahma, and Rudra? an objector may ask. The answer is: It is true that Iinidra is the ruler of the three worlds, and yet it is too well-known how he is in constant fear of losing this high estate. He is often curse-stricken, pays the penalty by suffering for Brahmahatya, is bound as a captive by Indrajit, and allows his sway to get into the hands of such beings as Mahabali. Such then is Indra, weeping and crawling in the dust!
Brahma is no better than Indra, for he is assailed by such evil genii as Madhu and Kaitabha, and is deprived of the Vedas which to him are his 'eyes and treasure.' And his head he allows to be ripped by Rudra (his own son).
Nor again is Rudra any the better. For he is to begin with, the Destroyer par excellence, how can he then protect? Water is wished for by the thirsty, but Rudra of the fire-colour offers himself to such thirsty worshippers of his as fire! He exacts horrid offerings from his devotees by saying, "Kill for me, roast for me." Banasura was his votary, so much so that Rudra pledged himself to guard him so that even 'the flower he wore on his head should not fade.' But when Krishna was hacking Bana's one thousand arms as if they were so many cactus stems, the boasted guardian Rudra shut his eyes and slipped away from his ward uttering, 'If life is spared, I can live by selling salt.' Again, he a sinner, cut the throat of Brahma, the guide of the worlds, his own father, and wandered about after such acts of treason in his won house, with the skull of his father fast clinging to his hand, from door to door, in search of a savior.
So,
Are they really God?
The answer is no.
If they are not God why Vedas praise them?
They do some sins, but generally the Devas are very righteous people. They are devotees of Brahman, protect the universe from Asuras, and are knowledgeable about Brahman.
Is there anything from Hindu scriptures especially in Vedas or Upanishads denies them as God.
See above.