The article does not even say what the ratios of the isotopes are. If it was depleted or uranium with an unenriched amount aka natural amount of trace U-235. Its not really any problem. Heck they make boat keels out of depleted uranium.
Article does not mention those details but if BARC has concluded that it was radioactive then it most definitely is radioactive.
[1]: https://indianexpress.com/article/cities/mumbai/mumbai-two-h...
[2]: https://indianexpress.com/article/cities/mumbai/two-held-wit...