I saw this particular verses from the Rigveda which says that an Asura named "Krishna" had a great enmity with Indra. I want to confirm that is this the same Sri Krishna or is it someone different? (I know that there are entities with the same name, that's why I am asking)
This apparently asura Krishna, mentioned in the Rig-Veda 8.96.13-17, if interpreted as a person, cannot be the Divine god (Bhagvān) of the Srimad Bhagvad Geeta.
This is because, Krishna was not killed by Indra, rather he chose to end his earthly past-times (leelas) through the medium of hunter Jara. Indra is nowhere involved.
This is narrated in the Śrīmad-Bhāgavatam Purāṇa, besides other scriptures.
मुषलावशेषाय:खण्डकृतेषुर्लुब्धको जरा । मृगास्याकारं तच्चरणं विव्याध मृगशङ्कया ॥ ३३ ॥
- Just then a hunter named Jarā, who had approached the place, mistook the Lord’s foot for a deer’s face. Thinking he had found his prey, Jarā pierced the foot with his arrow, which he had fashioned from the remaining iron fragment of Sāmba’s club.
Rather, Krishna is the one who destroys the ego of Indra in the famous incident when he lifted the whole mountain on his single little finger (ŚB 10.27)
On the contrary, here's an alternative translation by Dr. Tulsi Ram, which interprets the word Krishna as a non-person, and provides a metaphorical understanding of the verse -
अव॑ द्र॒प्सो अं॑शु॒मती॑मतिष्ठदिया॒नः कृ॒ष्णो द॒शभि॑: स॒हस्रै॑: । आव॒त्तमिन्द्र॒: शच्या॒ धम॑न्त॒मप॒ स्नेहि॑तीर्नृ॒मणा॑ अधत्त ॥ 13 ॥
- The dark passion of pride with its ten thousand assistants and associates comes, occupies the affections and suppress the emotive and creative streams of life. But, Indra, noble leader of men, the soul, with its great thought and action, takes this bully over, controls its violence, and covers it with sweetness and love.
To Conclude -
The Krishna of the Rig-Veda 8.96.13, is not the Divine God Krishna (who spoke the Srimad Bhagvad Geeta), but some other person after all, if the word Krishna is interpreted in a Proper Noun sense. Otherwise there can be a symbolic interpretation too, as mentioned above.